I made it clear from the beginning of my planning that I did NOT want children at my wedding. My fiance's sister was supposed to be a BM but got pregnant and is due in the next few days/weeks. The wedding is in 25 days and she wants to bring the baby. I don't know how to tell her she can't or if it's even ok to tell her that. I have other guest with new babies and they don't intend on bringing theirs. Thoughts...