Psycho Test

This is not a trick question. It is as it reads.

A woman, while at the funeral of her own mother, met a man she didn't
know. She thought this guy was amazing, so much her dream guy, that she
believed him to be just that! She fell in love with him right there, but never
asked for his number and couldn't find him. A few days later she killed her
sister.


Question: What is her motive in killing her sister? (Give this some
thought before you answer).

click on the comment to see the answer...only after you've given this your best shot.