In this world there are many married women who hate their mother in law. I've been thinking what would motivate a woman to hate the woman who gave birth to her husband.
The rivalry between wives and mother in law is mainly due to jealousy, mother in law considering that it has full rights over her son.
I have reached some conclusions on the relationship between mother in law in the daughter in law.
Reasons for women to hate their mother in law:

Mother in law is jealous of her younger rival;
Mother in law always give advice, it's best;
Mother in law she is the only one that knows what she likes her son;
Mother in law is the one who taught her son to be lazy, she did all the work for her son;
Mother in law is the one who protects her son, and he can not grow;
Mother in law knows best how to raise children;
Mother in law mix all things young couple.

These are just some of the reasons why so many women hate their mother in law.