(Answer the riddle with the first thing that comes to mind, or the second. But don't dwell on it for more than a few minutes, and don't read anyone else's answer before posting your answer even if you just post that you don't know. Really. This will be interesting tomorrow when I tell you what it says about you. This is fun, just in case you were in doubt :)

There is a grown woman. She goes to her own mother's funeral. There she meets a stranger, the man of her dreams! He's wonderful! Her soul-mate. He feels the same way about her. They get interupted. He vanishes into the chaotic crowd. She didn't get his name. He didn't sign the guest-book. She's distraught. Two days later, she kills her sister.

Riddle: Why did she kill her sister?