Very hurt over ex SD behaviour

[Amitolamummy]

My partner and I split up in Feb and a month later I took out a non molestation order against him because of the way he was treating me. He was emotionally abusive throughout the 6 yr relationship. He has 2 older children and we have a 2 little ones together too.
Today they were all meant to be seeing each other with their father for his birthday. My eldest and I went to loads of effort over the last few days making presents, cake etc. She wasn't there with her brother when I dropped them off because she doesn't want to see me. This is quite strange as she saw me last weekend when my ex had to jump start the car (its his) for me. She spoke to me perfectly normally and hugged me a few times, none of which was initiated by me. I had already been told she didn't want to see me so just said hi and left it to her.
My son was disappointed that she wasn't there as was I because it has ruined the plans that were made weeks ago. Apparently her mother is dropping her off later so she doesn't have to see me, but that doesn't make any sense because she will have to see me when I pick them up. I can't really understand why she was fine with me when it was her weekend with her dad, but when she is home with her mum she can't even sit in a car next to mine and not even have to look at me or talk to me.
I know she has been told everything was my fault, that i'm a liar, her dad is perfect etc etc as thats what all of his family will be saying. Her mum also blames me, even though she was also abusive to her.
I'm just so upset because I did everything for those children for 6 years. I always treated them the same as my own and went way beyond what anyone else was doing for them. I've been trying to just let it wash over me as I realise nearly teenage girls go a bit strange, but I can't after this.
My ex said he wasn't happy about it either, but I don't know whether to believe him.
I'm not sure what to do because I can't keep putting my sons through things like this. I know one thing for sure though, If I ever meet anyone with children again I will be running a mile! Nevr again will I waste my time on any child I didn't give birth to.

[Amitolamummy]

I name changed by the way. I used to get quite a lot of support from here a while back.

[Safmellow]

It's hard to accept when someone is blaming you unfairly. As you say, if she is a teenager she will be going through all sorts of hormonal changes, on top of feeling like her world is shifting after you and her dad split up.

I know it's very difficult not to take it personally, but I think it is probably because you were a massive part of her life, and did everything for them, that she has reacted this way.

In other words it's because she cares. If you can manage it the best thing you can do it remain calm and in time I am sure she will come round. Sadly you can't expect an adult response from a child. Hope you are ok.