Brother-in-laws not invited to wedding?

I think she's being very selfish. Husband and wife are one unit, which means that one cannotshould not be invited without the other. It is very rude. I bet if the situation were reversed and your brother was invited without her she would be pretty pissed and be raising h*ll about it. Think about going for your brother's sake, but I don't think I would go. Maybe send a nice card instead. It doesn't sound like she really wanted you there anyway.