Are You A Psychopath?

This test was given to me by my cousin. He said that this test was made by a Psychologist to determine whether you are a psychopath or not. 

So, if you would like to know something about you that you didn't know, something that is kept hidden within you, try to answer this question to unleash the monster in you. :) 

Ouh yeah, you'd have to answer this question by yourself. No asking, no googling, no nothing. Then only it's genuine. So, here goes the question. 

"At her mother's funeral, Zabedah *bukan nama sebenar* met a charming, young gentleman who caught her attention. She's attracted to him like a magnet. He was so fine and so her type. She could not get her eyes off him.

However, she forgot to ask his contact number. She knew nothing about him. Not even his name, not his phone number, not his email, nothing. She felt sad. Her mother has just passed away, and she did not get his contact number, the person she truly adores.

Things became worse when she got to know something. 

Late that night, she MURDERED her sister. 

Why?"

Feel free to drop your answer. 

P/s: I am a psychopath. I answered the question correctly. Beware.