Can a 13 year old use a taxi, or any other services that don't need an adult involved?

Let me explain. I have a 13 year old friend who's in a pretty tough situation and needs somewhere to go, like a homeless shelter. The thing is, neither of us have cars yet. I'm still in driving school, and she's still, y'know, 13. She's saved up around $150 for food and fees for like, a taxi or something, and stuff, but she wants something that could be cheap. She can't walk to a homeless shelter due to a breathing condition of some sort, and she has stressed to me that it's extremely important her parents can't find out. So, she does want to know if she can use a taxi or something like that, and if she can't use a taxi then what services might be available. If any of you could provide some information on this, it'd be great. Thank you!