well.. i have mixed feeling about the loli.. and i tend to hate evil brat character, because it's easy for the author to write off their evil just because they're kid...
It might be uncharacteristic for the old man to kill her, but i hope she gets her comeuppance later. She's horrible by any standard, she's like those kids who plays with knife but ends up getting hurt, except this one already used the knife to kill people, having fun with it (and she believes that her actions were right), and when the knife turned itself towards her, she cried and begs for help.