Dating an emotionally disturbed girl

I know this girl who is slightly messed up in the head, she has a bad home life and was recently kicked out of school, she is not like a rebel or anything and she was unjustly kicked out. On the up side she has a good personality and is not too bad to look at, I did date her for a little while I while back and it didn't work out. But since then we went too school together it was hard to avoid her, (a VERY small school), we ended up becoming friends, (then she was kicked out). Things are starting to heat up should I ask her out or not?

-Greg