I am marrying a man who has a brother, who is married. Everything I have read indicates I need to ask the groom's sister to be in the wedding party, but does this still apply if the future sister-in-law is also married into the family? Personally I do not think she will be offended if I do not ask her to be a maid, but I would like to include her in the wedding in a more significant role than the dreaded guest book assignment. Ideas?