Well, the answer is eay. She killed her sister because it was her fault.
When in doubt, blame someone else.?
Good answer, but not the correct one, this test is known as the 'psycho' or 'insane' test or whatever you want to call it and basically if you can answer it correctly it means that you think the same an insane person does, and the answer is that she met the guy at a funeral so, in her mind, if she goes to another funeral she might meet him again,thus she kills her sister to go to another funeral, screwed up but that's the how a psycho's mind works. And see that is why I can justify Anko liking Naruto for that, becuase I think screwed up like that. Or you could always heave her fall for him before she realized how much like Orochimaru he was and then have a bunch of emotional turmoil over her being in love with him and yet her knowing that he's exactly like Orochimaru, so that's a possibility if you want Teh Angst!