unpopular opinion here: but I personally don't put any fault on Sandra for flirting with her male classmates and getting their sympathy to do her bidding. yes, it's scummy that she's going for somebody else's fiance, and it really shouldn't be applauded. also, she was being bullied and in a crap situation at home, and if the guys wanna treat her: then I say go ahead sis
but - it's sickening/unforgivable what she did to her little brothers. her only reason for letting them die is that they were annoying (but they're kids, so what does she expect)