[RMadd]

Read this question, and come up with an answer. I'll post it in a few days' time, when a fair number of persons have shared their answers (the reason I'm doing so is b/c most of the fellas answered it "safely," while most females didn't, and yet considered their responses to be perfectly logical). Two other requests:
1) if you care to share, I'd like to know how long it took to arrive at your final response.
2) try not to look at other peoples' responses and, if you've seen this, post what your answer was the first time you took it.

This is not a trick question: everything is as it reads.

Here's the story:
A woman, while at the funeral of her own mother, met this guy whom she did not know. She thought this guy was amazing so much her dream guy she believed him to be just that! She fell in love with him right there, but never asked for his name or number and could not find him. A few days later she killed her sister.

Question: What is her motive in killing her sister?