I loathed Dawn for most of season 5 but in 'The Gift' when she was willing to end her life to close the portal and I reminded myself that she was only 14, I felt so sorry for her, it was Buffy in 'Prophecy Girl' all over again. Dawn had every right to go off the rails in season 5, every right. And when season 6 began and she told everyone to "back off!" when they were crowding the newly resurrected Buffy, I thought Dawn had matured into a caring, insightful girl and someone I could really like. Then she started stealing stuff.
Seriously, one of your parental figures is addicted to magic, the other has left the house because of this and your sister is so depressed that she wishes that she were dead and you think the best thing to do is shoplift for attention?! In season 5 she was moaning about being treated like a child and being babysat but then in season 6 she was offended that anyone would leave poor defenceless little Dawnie alone all afternoon or night or whatever? Yes Buffy was incredibly awful to Spike but Dawn was just awful! I was about her age when season 6 came out and she gave us all a bad name!