That's a good point.  Maybe she went crazy before being stranded alone in the wilderness, and that's why she killed her crew.  I've often also wondered why it is that the others don't seem to have to much interest in her.  They could obviously subdue her and keep her captive.  Are they fearful of her for some reason?  Or maybe she just doesn't have any skills or traits that they are looking for.  Or.....maybe she is one of the others...  I don't see how someone who has been stranded alone in the wilderness for 16 years not explore and know the island better than she seems to know it.  I mean, when she was looking for Alex, she didn't seem to know which way she was going.   I would think after 16 years that she would have found the little "others" community by now.  It's not like it's that well hidden(remember the scene of the plane crash from the first episode this season?)

Maybe she is part of Jacobs or Bens crew, i mean i cant believe she has been all alone on the island tht amound of time without seing them!!!! I mean she caught Henry Gale (Ben) the leader i think tht was a little co-incidental.....i think tht was part of there plan so then Ben can gain entry 2 the Losties!!!!!