A little history after being married 28 years (almost) I have 5 brothers and two sisters. Two of my brothers married wives that did not get along with our family, three did (including mine) Guess which two are not married anymore? One has since remarried and she gets along great with the family, the other is just recently divorced, give it time she will change or burn a bridge with your brother. I believe family comes first and if my wife doesn't want to play nice too bad.