Nick, I presume you are a man by your post and your name. I can't help but think you may want to rethink how you can help best. Being a mentor to girls who struggle with drugs or who have been abused is tricky territory for a man, simply because there are so many predators out there who look for vulnerable, needy people to prey on.
Most 12 step programs recommend same sex sponsors for just this reason.
I have volunteered at a woman's shelter, prior to that many years back I volunteered at a non-profit residence/program for unwed pregnant teenagers, where they received counselling and support and if they chose to keep their babies, they were taught parenting skills.
My point is, there are many places out there that help, counsel, and support women who need help.
The best way you could help these girls would be to offer financial support to the programs that help them or to volunteer your time fundraising or collecting clothing and donated items for these places.
It's nice that you have a good heart, just please be careful not to put yourself in a compromising situation.
Hugs