Job Corps
Why doesn't she look into Job Corps? They take in homeless people all the time and she'll have the opportunity to get a highschool diploma, drivers license, free access to laundry, free clothes, an allowance, and a certificate for a decent job all for free as well as shelter and food. They can probably provide her assistance to get free or extremely discounted dental care for her meth mouth. They obviously won't allow her to do meth, and she'll actually need to shower regularly (w/ soap) and practice decent hygiene, so I'll assume the program is out of the question for her, but I can see it making her quality of life much better. She literally has a shit ton of resources available as a homeless teen/young adult.