Are you a Psychopath? Answer this question and find out! :)

This is a genuine psychological test.

It is a story about a girl.

While at the funeral of her own mother, she met a guy whom she did not know.

She thought this guy was amazing, so much her dream guy she believed him to be, that she fell in love with him there and then … A few days later, the girl killed her own sister.

Question: What is her motive in killing her sister?