"Psychological Test" joke

This is a genuine psychological test. It is a story about a girl.....

While at the funeral of her own mother, she met this 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?
DON'T Scroll down until you have thought what your own answer is to this question!!!!!
(No trick answers here.)

Answer:
She was hoping that the guy would appear at the funeral again.

If you answered this correctly, you think like a psychopath. This was designed by a famous American psychologist used to test if one has the same mentality as a killer. Many arrested serial killers took part in this test and answered it correctly. If you didn't answer correctly -- good for you. If your friends hit the jackpot, may I suggest that you keep your distance.

PS If you got the answer correct, please let me know so I can take you off my mailing list.