I was going to say it’s quite common for teens to say they want to live with other people but reading on it’s obvious that there are some massive issues here!
My DD is the same age as yours. I also work with teenagers.
It is not normal that a 14 year old has SS involvement, sees a therapist, has had pregnancy scares and an abusive ex!
There are obviously a lot of serious issues that you are downplaying and some of which will stem from family life.
You know this which is why you befriended her friends parents and they’re offering for her to stay at theirs - no one offers to take on a teen (especially one with so many issues) if they didn’t think she needed help.
You need to seriously look at your home life either now or what happened in the past as you sound in denial.
We can’t give you any proper advice unless you start being honest with yourself.
My mum was in hospital multiple times because of DV, we often had to leave in the middle of the night and sleep in the car, we would drive around knocking on everyone’s door to find the OW and have screaming and fighting over us, we had to give statements to police and many times we had to live with my gran. My mum also had MH issues and we’d have to steal food to eat - we didn’t have the worst childhood in the world but it definitely wasn’t the best yet my mum will say we had a really good childhood because she’s in denial/blocked out all of the bad bits.
Do you have any family members she can live with?
I’m really concerned that she’s having sex and relationships with boys that are no good and this is going to continue as she’s going to try and find somewhere to live.
If an older man says she can live with him she’s going to jump at the chance.
For now you need to really listen to her as teens need to know they’re being heard and ask if there’s anything that will make home life better.
If possible you can compromise and see if she can live with you during week days and maybe at her nans on weekends if she’s behaved.
I’d also help her to look for a college with accommodation for when she’s 16 so she’s staying in education and away from her abusive ex and she can see that you’re helping her with what she wants.
You can use it to bond with each other by researching them on the internet and going to see them ready for when she leaves school.