Sounds like you have a great WC but......I don't think she should be doing any other weddnig on the same day, even if it is just a vow renewal. I do feel for the other bride but it shouldn't inconvenience you. I can't imagine not having a WC be there for you for the WHOLE TIME! I would talk to her about it, let her know your thoughts and let her make a decision about what to do. Can she get someone else to oversee the vow renewal? I don't think you sound bratty at all. I'd be really bummed too!