Yeah, that's awkward. I had a friend call me two days ago asking me "why in the hell am I not in your wedding party because when I get married you would definitely be in it". Now, I have ALWAYS been a blunt person, even too a fault some would venture to say, but I gave her a mild version of the situation. I say this to say it is harder than I thought it would be to have that conversation. But, I never once thought about just putting her in the wedding to spare her feelings. This is your day, like everyone else has said. The people you pick are supposed to be people who are close to you, by your side and most of all, supportive and helpful throught this planning process. Good luck and happy planning!