A young woman is attending her mother's funeral. While there, she meets a man she has never seen before and falls in love immediately. After the funeral she tries to find him but cannot. Several days later she kills her sister. Why does she kill her sister?

“She was angry at her sister for not being there during the funeral.”

This guess misses the key motive of trying to see the man again; the anger does not explain the drastic action taken.

“She was jealous of her sister's relationship with the man.”

This answer assumes a rivalry over the man, but the riddle indicates the woman had not met him before the funeral, so jealousy is not a factor.

“She wanted to inherit her sister's possessions.”

While inheritance could be a motive for murder, it does not align with the riddle's emphasis on the woman's desire to see the man again, which is the central reason for her actions.