how does a homeless person get off the streets if they dont have their birthcertificate?

Im not the one homeless, but someone i know has been homeless for yrs where i live, this girl told me she cant get a birth certificate, she was born in another state, i think her mother wont sent her one for some reason, and because of that she cant get an id either to get help to get a place, just wondered if theres a solution to that problem, i hate to see her like that but in my apt building we're not allowed to take in the homeless. any solutions to that so i can tell her how to do it? im not even sure i could get it for her cause i dont want to do anything illegal, any suggestions?