I discovered a Friend of mine likes to burn thing, It's nothing much just matches and little bits of paper burnt one by one in an ashtray, She swears she's careful and she used to do it when she was younger at about 7 and 8 but she only just started doing it again, Tonight was the second time. She said she just wants to do it when she's kind of bored but I'm still worried, What Do I do?

Well, asking for help on a fanfiction site is certainly a step in the right direction.
If she's still young tell her parents, if not there's really nothing you can do.