Someone asked my that question a few years ago. My answer was: the man was a doctor and told the sister that her other sister had terminal cancer. So in order to spare her long suffering, she killed her sister. I was told that was not really the expected answer Please Register or Log in to view the hidden image! sparkle
the most logic answer to this is >> she fell in love with her brother! she didn't know she had one. she killed her younger sister out of revenge, because the younger sister killed her mother. it was/is a war between families and she is/was saving her name and love. is she the last of her family? get her out of there please!
She killed her sister because she was disturbed...... and unstable.. and had many an influence in life which allowed her on that day to deside to kill. the fault lies in the hand of humanity in general.. for allowing the negative influences that allowed a woman to even consider killing her sister... to determine whether it had anything to do with the mothers death, or the man she wanted to marry requires more information. -MT