YSD has been deteriorating drastically over the last month. I had my suspicions by the way she was acting that OSD has been manipulating her.

OSD doesn't have anyone left because all her friends have abandoned her. Which is what happens when you have a personality disorder. They are older now and can see how she is toxic and they have stopped speaking with her. 

So she is now working on bonding with YSD who is very easily manipulated and younger. When YSD talks she is literally repeating what OSD would say. It has even come out that her "issues" with me are issues I had when OSD lived here. 

YSD only keeps bringing up things that happened between YSD and myself or her father as reasons for why she is angry with us and being disrespectful as if they happened her.

She is clueless that she is being used by her sister because her sister is angry that I still had a decent relationship with YSD and would do things with her and for her. 

YSD has no idea that when OSD pulled the same nonsense I made her eat her words. Basically said if you want to be grown, i will treat you like you are grown and have stuck by my word for the last year. She wants or needs anything as a grown up she can figure out how to get it. Plus as she reminded me often I am not her parent. So I wouldn't want to offend her by doing anything that a parent would do. 

YSD got her first taste of the consequences of her words and actions last night. She sent me a long text informing me that as a 13 year old adult,  she is going to live her life as she pleases and her father and I need to accept that otherwise she will only get angry with us and she doesn't let go of her anger very easily.

My I ly response to her was I don't know why she is sending that to me I'm not her parent and could care less if she wants to make bad decisions. She needs to have those conversations with her parents. 

Apparently by her response she was butthurt by my reaction. Unfortunately she hasn't seen anything yet. She forgets she asked for me to buy her sneakers for bday and to take her out. 

When she reminds me of this which she will, I am going to have to inform her that doing so would be something a parent would do and I wouldn't want to upset her by trying to act like her parent. 

She wants to go skiing and up north I am going with DS. When she asks to go I am going to inform her she absolutely can go whenever she wants. After all she is an adult now but she is going to have to make her own plans and arrangements because me doing so would be treating her like a baby and I wouldn't want to upset her. 

SO is aware of all of this and says he is completely supportive. He is so angry with her right now because she purposely stayed up all night because she plans on sleeping all day and skipping school to show him he can't tell her what to do.