My fiancee is tired of me stressing over this so I've opted to get an outside opinion. My fiancee's twin brother is getting married a year before we are. I'm a bridesmaid in their wedding but the bride doesn't have many close friends. I on the other hand, have multiple close friends I want to include in my wedding party. Am I obligated to include my future sister in law? I'm worried she and my fiancee's brother will be upset if I don't ask her. We're not close and I've never spent time with her without the boys. My fiancee doesn't think I need to include her. He also has two older sisters (both older, married with kids) who I'm not asking to be in the wedding. They don't expect to be asked.
Thanks for any help! I'm so conflicted.