Runaways ran away because they were getting molested so much they had to cut school to make time for it, am I wrong? So when they finally steal their stepdad's crank revenue and get on a bus, they take it to Hollywood usually, to become famous because if they're rich and famous then everyone will listen when they say "no." Some might go to Seattle if they wanna be rock stars instead of movie stars, or New York if they dig musical theater (Note: Just because everyone in musical theater has been molested, it does not follow that everyone who has been molested digs musical theater).
So where do you come in? You have to pick a runaway and try to keep him or her from becoming a hooker. At least for a little while. The only people who talk to runaways are pimps offering free soup. Yeah, some pimps just like to give runaways free soup, but others want to convince the runaways to have sex with strangers for money (IT'S THE FUCKING TRUTH!!!). So if you stop and talk to the runaway shivering in your bus shelter every morning, he/she will think that maybe there are people out there who are just as nice as pimps and he/she will wonder if there are more options open to him/her than being obligated to have sex with strangers for money in gratitude for free soup.
Switch things up. Offer your runaway some pie. Or show up one day with a bowl of your "World Famous Chili" and act like you're only offering it because you're so proud of the fact that you know how to cook wet beef that you make everyone you meet eat some. This way the runaway won't think you're trying to manipulate him/her at all. You're just an annoying person with few talents.
The important thing is not to push. Runaways are kind of snobby in that they think everyone wants to fuck them. So don't offer to let him/her crash at your place. He/she will think you're just like the rest. Maybe give directions to a shelter or call the police or leave little post-it notes on his/her blanket of newspapers that say "You're special and no one can take that away from you." Before you know it, you're gonna be reading your name in the dedication of a tell-all book.
Happy Befriend A Runaway, BUT DON'T PUSH!!! Day!