I have read other post trying to find an answer to my question and I have found similiar questions but mine has a slight change. I asked my cousin who lives half way across the country to be in my wedding 6 months ago and she recently found out she is pregnant and will be 5 to 6 months along by the time my wedding is here. The place i picked my dresses from does not have any maternity dresses in the same color and also the reason i picked these particular dresses because they tie up in the back just like mine does even my flower girls dress ties up. I'm really happy for her but at the same time I want all my dresses to match especially in color. I don't know what to do.
Perhaps this is something that could be altered. It is amazing what some can do. So, it may not be a problem. If it is, then perhaps she can find a dress that is not from that store, but in the same color.
Typically we do have our ladies wear the same dresses. But, it wouldn't be so terrible for the one attendant who is pregnant to be dressed a bit differently, especially in an informal wedding. Yes, it will be obvious. But a wedding is a symbol of cherishing relationships and this is a special relationship--mother and child.
Other than that, if you can't find a dress and the dress you chose can not be altered, you could speak to her and ask her what she would like to do. She may suggest that she steps down.
I would definitely recommend approaching a talented seamstress about altering the dress or making a similar dress out of a material that is a close or perfect match.
If for some reason it can't be altered, think very carefully about how important the cut of a dress compared to the importance of the relationship is to you. 5, 10 or 15 years from now, the photos (which are primarily taken from the front) will hold great memories, but they won't be worth nearly as much if you don't have your cousin there to share them with. Shayna Walker, Williamsburg Wedding Design http://www.williamsburgweddingdesign.com