Nope. Hill to die on.  You put a firm boundary in place with him and be ready with facts and figures on how much it will cost him to choose SD over you and bio. Alimony+ child support+ health care+ daycare+ college fund and any other costs you can think of.  The bigger the number the better.  If that doesn't do it then you get on with life leaving him behind.

Why on earth didn't BM have her arrested and baby go into foster care?   Sounds better than what that baby has now.  

When DH and I got married our kids were DS16, DD14, DD7 & SD6. We/I had a very stern conversation about me never accepting babies born to a teen mom in our house. I was confident in my ability to be proactive with my girls about birth control and making smart decisions. I was less sure about BM's ability to do the same. SD16 has been sexually active since she was 14 and got on birth control about a year later. We had to take her to my OBGYN to get the scrip because BM wouldn't do it. 

I love my DH very very much, however, I have one child left at home (DD16) and would leave him before I would raise a grandchild that SD16 gave birth to. I simply could not do it. 

I accept that my view is narrow and somewhat selfish, I am ok with that. I am so close to having an empty nest and am looking forward to it. I cannot stomach the idea of all our sacrifices being derailed by something so easily preventable. 

I think you need to let your husband know, before he agrees with SD to allow her to move back in with you, that you are not OK with it. In your situation, I'd take the 5 yo and leave if he didn't respect your feelings enough to tell SD no. Make sure he knows your position.

"DH, either I live with you or SD does, but not both. I won't live with an entitled adult. If you want to live with her, I suggest you find somewhere else to live now."

Make it as plain and simple as possible. He can enable his adult daughter, but he does it alone. No excuses.

Last thing she did was punch her mom in the eye because she wasn't breastfeeding the baby and the mom threatened to call child services, she went insane and punched her mom repeatedly in one eye. 

Was SD not breastfeeding, using formulas? That is not a child services issue. Or, was it that the baby was hungry and she wasn't breastfeeding him/her?

Where is the father of the child in all of this? Involved? Not involved? Paying child support? 

Has SD applied for SNAP benefits? WIC? Public housing or section 8? How does she plan to support this child? Going to counseling for her postpartum depression?

Helping out a young parent is one thing. Occasionally buying diapers. Occasionally treating to something.  Enabling, letting them move in with no plan, is another. 

SD has a safe place to live with BM. (Unless she turns violent again. If she does BM should call the police.) There is no reason to move back to Dad and SM's house. Wanting to is not a good reason. 

No SD.  If DH wants to take care of SD he get a apartment  for both of them and goes to live there.  Do not let SD move  in. It will be the end of your marriage either way 

My guess is BM is holding the line, or if not, is beng verbal about SD58's shortcomings.  SD probably feels life would be easier and less stressful at your house.  I agree with the others, make it plain to your DH that if she moves in, you will leave him.

Its a full sentence.

Not wise to bring her and her child into your home. She is all grown UP now since she made the decision to become a mother at such a young age. Adoption maybe would have been a better option. BUT

The best way all the parents can help her is----take her up to social services. Begin the process of going on the list for housing, WIC, foodstamps, Welfare if needed, day care vouchers. All this will lead to paternity testing, child support and maybe a court order for visitation with  dad.

She will have to work at some point. With all the above in place, Granny will not be a babysitter, your dh wont feel guilty and become a babysitter either.

I am so sorry you are faced with this. Many young, young parents expect Granny and Grandpa to be parents again. DONT DO IT. Do not let her move in, they will not leave.

Set her up for success----Social Services will help.

"No husband!! You don't get to tell me to eff off about having another child because you want a decent retiremnt but then have your adult daughter and her newborn live with us when they are not our responsibility!! 
 

you don't get to tell me no kids because of money but are willing to fork out the cash for caring for a lazy arse adult and newborn grandkid thats not our job!!"

and believe me if she gets to move in you will be subsidizing them with your uterus and your finances.. to top it off she punched her bio mum in the face. You have a minor kid together so imagine this op... you tell sd to clean up after herself because house is a pigsty and she is being a lazy bum and she tells you to fuck off and you tell her to clean up and she punches you in your face. Wanna take a guess what your husband will do? Likely nothing and excuse it saying "oh she didn't mean it!!"

what happen if she knocked you out and you have your 5 yr old being subjected to this violence.

my husband doesn't get to tell me no more kids when he is off handing monthly allowances to an adult 22 yr old who has finished university studies and a 24.5 yr old who has been in graduate fulltime employment since feb last yr earning $2900 per month and guilting daddy for her monthly $1000 allowance where she is earning more than a clerk or secretary... nope that is my friggin hill to die on.

i will never sacrifice my child bearing opportunities for feral lazy arse disrespectful skidults

Thank you for sharing.

No one should have to go through what you are going through. I hope your spouse makes the right choice, stands firm, and stays by your side. It sounds like your step daughter is cruising toward a really bad life and she desperately wants to drag everyone else down with her. Please, I pray that you aren't caught in the whirlpool. 

Stay safe.

If yoiur DH insists on taking her in so he can take care of the baby, remind him that the baby HAS a father and that it's not him and then trot out the reasons that he refused you a second child and let the words hang in the air ... He also needs to hear that there is only ever ONE queen in a castle and that, in this case, it's YOU.

I don't understand what is hard about this for you - "When SD lived here, she did nothing but sit in her room, and I'm not supporting and caring for her baby.  Move her in and I move out."

Don't fall for his BS.  She has a place at BM's.

There is so much wrong with this situation. Sorry but once you are grown enough to have baby, you need to either be super grateful and help out if you are living with your parents in every way.

She needs to go to her local WIC office and start asking where she can get help. Get in section 8 housing, get daycare assistance, either get a job or get some kind of certification (cosmetology, phlebotomy, CNA, Accounts Payable/receivable- whatever). She needs to get her custody and CS situation figured out too. Maybe there is more help there for her to get her life together for this new baby. 

I would absolutely not allow her to live with me. 

Expect her to pull 'you wont see your grandchild'-----(they use that when they dont get what they want)

DH reply must be:  OK, I wish you well. Do not ever use a child as a pawn again. BYE

It is your home with DH, so he can't make a decision for his daughter to move in unilaterally. If he does, you should kick him out, instead of moving out with your child. 

Also, is that baby okay in the home with your SD? Not advocating for you to take the baby in, but maybe you should support BM's calls to child services...from the sounds of it, it could be more than the breastfeeding issue.