15 year old gone to live with her dad

[Lemonmelon1]

I have 3 dc 15, 11 and 9. I split up from the children's dad over 3 years ago and they've always lived with me whilst seeing dad eow and one night a week.
I remarried last year and also have a younger sc.
my children are all on the spectrum and my youngest has other complex needs too.
When I left the children's dad my eldest wanted to disown him and wanted nothing to do with him. I fought hard to encourage her to see him and to keep their relationship alive.
She has now turned around and said she wants to live with him. She's decided to spend 2 nights a week with me and the rest with her dad.
I'm heart broken. I never thought this would happen.
It feels like he's sold it to her that they'll have weekends just the two of them doing big adventures that I can't do due to my health and also my youngest needing me so much.
After spending so much of my life dedicated to my kids this feels like a real kick to the stomach.

Has anyone else been through this?

This will probably have alot to do with you getting remarried and possibly bringing a SC into the mix along with her siblings needs. Teen girls in particular struggle with having unrelated men in the home, it changes the dynamic massively, let alone an autistic teen girl.

What is the home environment like, is it calm and quiet or busy and noisy due to siblings and sibling with additional needs? Does she have her own space or share? Does she get quality time with you or left to get own devices as the oldest? If i had the option to live in a calm and quiet space over a chaotic one id know which one i would choose regardless of the parent that lived there.

Unfortunately you dont have a time machine so it's just a case of making home welcoming when she is there and making sure she has her own space that is quiet so she can get on with studying etc without being disturbed by her own siblings or the SC. It's quite normal for teens to flip flop from one house to the other

Just go with the flow here. Look at this through her eyes. She's going to get more individual attention in a quieter environment. There's also the possibility that the grass seems a bit greener for her. She may change her mind too! Giving her autonomy over this with no animosity or recriminations will be the best way forward.

She has her own room and her own space here. She currently isn't in school as we are fighting for a unit space for her. She's still registered with her school but that's a whole long store and battle I've had with them.
She will be with me Monday morning through to 3.30 Weds and the rest with dad who works full time so she'll be on her own all day Thursday and Friday.
I know she has struggled with accepting my husband. He's been so lovely to her and supportive it's hard to see. My other kids love and adore him and would be heartbroken if we split.

Agree with @Mabelface
He sounds like a bit of a "Disney Dad" and yes will be different when she is there almost full time.

Yes I’ve been there. My DC was 18 at the time. It was a disaster as my ex was still the selfish person he’d always been and my DC was affected badly. It’s normal for children to love their parent and want a loving bond. They’ll come back, remain open, arrange shared mundane experiences when you see her, make a cup of tea together , watch her favourite film, say you like her. She needs you and is lashing out.

@Singleandproud
As she isn't in school at the moment she has me to herself all day during the week but she chooses to stay in bed until around 11. I've been making sure I do nice things with her and spend lots of quality time with her
Once the younger two are home I am caught up in caring for my youngest and by the time she's in bed I am exhausted tbh.
But yes, she has her own room which has been kitted out exactly how she wanted it. She's also been spending a lot of time with my middle child staying up watching films etc so they will lose that bond.

does she have issues with her step dad? You say you split with your ex 3 years ago, but remarried 1 year ago. That’s not a very long relationship with step dad before marriage. The age of 12 is a very difficult time for a child to go through a parents’ divorce, there’s been tests done on that. Lots of changes with hormones, school, friends, etc that comes with that age, then a parents divorce on top, followed quickly by a new “dad” figure. A lot of changes in a very short time, during a pivotal time of development. That’s a significant amount of change for a child to process, especially when the child has additional needs

Not saying all this to put blame or anything, OP, but definitely an angle to consider ie how quickly her life changed & how quickly this entirely new person (and family) became such an important figure in her life despite not knowing him for very long

Why not embrace the fact she has made up with her father and wants to spend time with him? She's not abandoning you. She doesn't love you any less. My step kids moved in full time as teens. It was complicated but while they both had a rocky relationship with their mother for a while it was great they could step away for a bit. She's a teen and Theo don't always think logically or sensibly, but this might be a real chance for her to have her dad in her life.

Ye I totally get she's had a lot of changes the last few years on top of her hormones and a lot of mental health issues.
It is lovely that she's going to spend more time with her dad I guess I just wasn't expecting her to move out for quite a few years yet and I'm going to miss having my first born here the majority of the time.