Tell her it will be alright and push for her to finish school, but let her make her own decisions, I would make sure she knew I was there if she needed me but that I was't going to take over.
I had DS at 15, to the rest of the world it looked like my parents were very supportive but actually they took over and it damaged our bonding because nothing I did was the way they would have done it, down to I can remember being screamed at for buying my baby the wrong brand of nappies (before he was born, so not even like I'd bought ones he was sensitive to, I'd bought pampers because they were on offer, mum always used huggies for us) and we had a screaming row in the doctors because mum is an anti-vaxxer and I'd taken DS for his jabs, they very much acted like DS was theirs not mine.
DS is doing brilliantly at school, he's doing GCSE's, plays for a local football team, doing his DofE, does some voluntary work, is generally pretty damn awesome.
I had to adjust my plans obviously, and because I fell out with my parents have had to earn and pay for everything myself since leaving school so I am a few years behind where I planned to be but I finished school, went to college and then did my degree through the OU (self funded so no student debt), I'm 30 now, I am doing my masters and I work with children with SN. I'm married (not to DS' father) and have another child, a dog, some cats, a house, pretty much as I had planned my life as a teen (except bills and children are bloody expensive so there are a lot less pretty clothes and nice meals out than I'd imagined lol)