Are you her direct supervisor or manager.. is your role managerial?  If so, why are you not able to write her up or discipline her?  Or is your role more administratively senior.. reporting to management on performance etc?  So, maybe she sees your attempts to coach her as micro managing and overstepping your role?

If you are her manager.. and in fact in a role intended to coach and improve her performance.. you probably need to stop messaging and have a real life meeting and conversation with her.  You need to do it face to face.. or as close to that as possible(if you all work remotely).

Has your company given you any training on how to coach your subordinates?  How to help them improve their performance.. and how to deal with touchy subjects like "attitude".. or ignoring communications?  It might be good to take some kind of training like that if they offer it (if you have not already).. so you can get some idea of how to coach someone in a way that leaves them motivated to do better.. instead of just feeling "scolded".

If you aren't in a real management position over her.. just more in a senior role within the group..for performance reporting.. then perhaps you just need to let her lack of reporting or performance speak for itself.  Instead of instant message.. send a reminder to your team a day or two before the metrics need to be uploaded.. (so no one feels targeted.. everyone gets the message).  with the deadline.(which should be in advance of when YOU need to compile for management.. enough time to reasonably follow up for missing data).  If the deadline comes and goes and she (or others) haven't updated it.. an individual email reminding them it needs to be done in the next "hour.. two hours"(whatever is reasonable).. and then if it is still not done?  Your report to management is done.. without her data.. and you make a note of anyone who has missing data.. you have your two emails as support for your attempt to remind.. and to remind again.. so they can do with that what they may.

If you are in charge of time keeping.. report missing time to your management if necessary.

But.. back to the kind of meeting you need to have.  First... you don't know.. maybe she is dealing with some issue that is causing her to have problems performing.. maybe an illness?  Maybe a loved one who is ill?  Maybe a relationship problem.. like steplife.. maybe a child problem.. 

You can tell her that you are talking to her because while she can be a great and productive employee, that recently, there have been some inconsistencies in her performance and you want to know how you might be able to help her get back on track more regularly.  Remind her that your company offers.. employee resources if she is dealing with pressure from outside of work (if you do).. ask her if there is anything you can do to help her be more successful.  Remind her of rules regarding submitting performance data and expectations of keeping certain hours as scheduled.. Thank her for being willing to work with you to improve this performance.  Be sure to point out things she does WELL.. it should not be all about pointing out her flaws.. which is what she may think she is seeing now.

Recommend the above advice, and that you follow up on the IM's with emails that include screenshots of your IM's to her so it's documented. Also immediate email re-caps to her after any one-on-one meetings so you have documentation of what was said, in case she tries to lie later and gets you into a "He said, she said" investgation. 

Co-workers & employees can be tricky!

Heh heh sandwich method. As someone who also manages people... sometimes it's damn hard to find bread around here. 

Ahem...

"You done a good job wiping your feet before you come into the office but unfortunately you've cheated the company out of 80 hours of paid labor this month as you keep sneaking out the back door after lunch. Still we appreciate you keeping the office refrigerator cleaned out while you eat everyone else's food that don't belong to you..." 

to prior leaders not documenting performance issues. Or even worse, companies that pull reprimands or performance write ups after a period of "good" performance. Nope, those have to stay in that employees file for their entire time with that company.  Far too many performance problems will get and keep their shit together for as long as it takes for the write up to expire.  Then... the same shit surfaces.

I am glad that you documented and escalated the performance issue with this individual. Never forget, everyone you work with is your competition and many take the position that you are to be undermined.

I am a developer, I build talent and leaders. Fortunately far more than the majority are quality people and quality leaders. However, occassionally someone that you invest in will attempt to undermine you in an effort to take your job or undermine a future opportunity for you to minimize their own competition for those roles.

So.. document, document, document.  Do regular performance updates with each of your direct reports so that when annual reviews/appraisals are done there are no surprises. If they require formal coaching or reprimands, refer to your performance updates, guidance, and discussions and refer to them by date and topic when necessary when doing the annual performance appraisal.

I also utilize a "Memorandum for the Record" file system where I write a memorandum referencing the date, who is present, and what is discussed or what occurred.  If necessary I forward a copy to my boss or HR when I decide a situation warrants it.

Rarely do complainers document anything until they engage HR. Usually their report is verbal whining, etc...  that is put into a very brief form.  A memorandum for the record with detail, sutuation, results, who said what, and what the leader stipulated that others were instructed to do, saved in both Word and PDF, will bolt HR and Sr. leadership into addressing the problem child rather than deflecting to the problem child's direct report leader as the problem.

I have had Sr. HR and Sr management try that with me. They tend to get very quiet and supportive when they hare handed a printed copy of the "Memorandum for the Record". 

My lesson moment on this was when I inherrited an organization that had a number of performance problem employees who were transferred to the org prior to my being hired to lead it.  When their performance crap resurfaced and I could find nothing but strong performance appraisals I set up 1:1 meeting swith all of the problem employee's former leaders. The ones that were still with the company.  All of those managers had extensive experience with those same people and their performance crap.  When I asked why there was no record of it and nothing but 3 or better performance appraisals in the employee record... I got sheepish carpet scoping. They all then recounted that they had written the performance problem up more than once then would pull the write up after 90days of drama free performance.

I already had the Memorandum for the Record system in place. I then started doing formal write ups, reviewing those with the problem employee, then notifying them that the reprimand would remain in their file.  It would never be removed and if they repeated that infraction again... ever... I would terminate them.

Suddenly, my team stabilized, everyone did their job, and we collectivley outperformed the other identical organization.

I did have a major incident with a problem employee about a year after I did the interviews with the prior leaders of my problem children.  My boss, the HR Director and I met regarding the problem and the complaint the employee made.  We then had a meeting with the same people plus the employee. The HR Director stabbed me in the back and scolded me and the problem employee that we had to learn to get along.  I immediately ended the meeting, send my employee out, and addressed the HR Director that it was unacceptable that they had stabbed me in the back. I then slid the printed copy of the Memorandum and the formal write up I had done and reviewed with the employee that was in the personnel file and would not be removed. HR Director got angry and told me that the record would be removed. I told them to read the Memorandum for the Record in detail becuase the write up was referenced and included in the Memorandum.

Suddenly, the HR Director got far more collaborative in addressing the problem.

Hopefully you will not get into a contentious interface with HR over a crap employee.  But, it is better to have it and not need it, than need it and not have it.

I may go after my former employer legally as soon as I start my next role.  I have advice from a labor attornney that the lost income for my job seach supports compensatory damages and the hostile work environment, wrongful tgermination, and co-employment issues could add punative damages.  The attorney grinned when I provided the pile of Memorandums.  I have never sued an employer before, I'm not sure I will. But... everyone I have spoken with, mentors, lawyers, colleagues, etc... advise me to go after them.

Not sure yet. But I may.

I have been part of a few corporate legal actions where my Memorandum's have been included and used by the company I worked for at the time in defending a law suit from a customer.  I keep the Memorandums, Snip emails and instant messages, and put them in a dated file on my hard drive. I back my harddrive onto a personal Terabyte drive ~quarterly.  I still get calls from the corporate attorneys of a company I was with for 11yrs. I left that company in 2015.  A client company sued to hold my former company accountable for infant mortality equipment failures that my company did not cause. The owner company had contracted with us to do condition assessments and preservation maintenance on equipment they had mothballed when they canceled a $Multi-billion industrial project. When they canceled they abandoned the equipment where it was and paid storage. A lot of it was outside.  

After 5yrs the owner/cient relaunched the industrial development and engaged my firm to do the build. I was Project Director for equipment inspection, preservation, and maintenance for all stored equipment and critical spares that had been purchased during the original phase.

We set up the inspection, preservation, and maintenance schedules, coordinated it with the owner and my teams were travelong all over the world to assess and maintain. After several months my teams started arriving at storage locations to find the equipment gone. The owner had it picked up and shipped without informing us.  For some reason I had the only record of the owner shipping the material, not allowing us to assess, preserve, and maintain.  Also an email from a Sr. customer executive climbing my ass  and instructing me to stop all assessment, preservation, and maintenance.  When the corroded crusty crap that, though "new" and unused, was installed and commissioned, it started failing.  So, the owner company went after my former company.

I had it all in several Memorandums with dates, names, etc... indluding Snips of emails, written transcripts of telephone conversations, etc...  

Document and retain. It can be a benefit for you in dealing with challenging employees or a spineless HR or Sr. management team. It can also be a benefit to your employer.  Even years later.

Though you do want to comply with record retention rules for your company,  I consider a Memorandum for the Record to be my personal record.  I do not send them electronically usually. If I am sharing them with HR, Executive Mgt, etc... I usually print it and give them a hard copy.  That allows them to admit that they have them, or not. But they know I have them.  When I give a printed copy... I write a MftR documenting the conversation where I provided the printed copy.

It sounds like it takes a ton of time, it really doesn't. As not all that much that goes on warrants an MftR.  In  the 20+yrs I have been using the MftR system, I have spent no more than a ~dozen or so hours on writing them.

Or as they say stupid visor.   People need other people to hate, blame there faults and problems on others.  You know that story.

Peopje under you supervision, will hate you. That a fact. Hope you are getting enough lot of it.  I became a supervisor in my 30 'S  Hing like 40 people under me.  Therlin some one older then your father what to do,  takes getting used too.

Absolutely, ESMOD!

I was blessed with that type of supervisor for the last two decades of my working years. Our agency's standing among more than a dozen satellite offices was consistently number one, all because of the best boss I've ever known. He was almost laisser-faire in his management style; giving us nearly free rein, liberal with days off/early leaving, supportive, honest, just and kind. One of our best anecdotes about ‘Frank’ was an occasion when he ‘suggested’ how an employee might make an improvement in one of his duties. Afterwards, our co-worker told us what had been discussed and, puzzled, asked, "Has he (‘Frank’) just told me off?

‘Frank’ had a wonderful sense of humour and a big, booming laugh. When he died, his funeral was 'standing room only' in a big church.' We loved him. I still think of him and smile, 20 years after his death. So yes indeed, ESMOD, it’s possible to have a supervisor of whom no one speaks ill.