Am I Able To Get Custody Of My Friends Teenager As A Non Family Member?

I hope I put the right flare. So here's the situation:

A friend of mine decided she gives up now she's living on the streets and she says she doesn't care about her daughter who is a teenager and is calling DCF to take her. I(22f) currently have a son(6) and know that I am capable of taking care of another person and would be very happy to. Do I have to go through the entire lengthy process of proving my ability to support her if my friend willingly signs her rights over to me? And she won't be able to afford child support most definitely but will I be able to receive any financial aid to support her daughter in this case?

I feel for her daughter very much and want to be able to provide the care that she needs and make sure she has emotional support in this period. I know I'm young but I've been working hard to be the best mother that I can be for my son and I do a kick ass job.