Can you solve this riddle?

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

Question:
What is her motive for killing her sister?

i believe he would go to her funeral

I dont know what the motive is!! Tell me!! I need to know now!

cman got it right!

CRAP! someone already had it.