Husband wants Divorce

Hello, This is for my brother. He married to a girl very happily with both the families acceptance but unfortunately she started having problems with her in laws which was not liked by my brother some of the time the matter exceeded the patience level which caused differences between them and it lead to seperation. After sometime he got her back home and everything was running smooth in which she got pregnant and delivered a baby girl. After a couple of months she again had problems with her in laws and she went to her mom's place. She send a notice to my brother's house stating that she was physically harassed and also filed an inappropriate cases to all his family members. My brother went court for hearing in which he proved that the the blames were invalid and she is doing don't know for what purpose and during these court hearing for about a year she went to meet her daughter every time ad fulfilled every need and he is done with his patience. he needs divorce but he is not asking upfrontly becoz she will claim a huge amount of alimony. Please suggest he needs to get rid of matters and move ahead.