Maid of Honor Bailing Out?

Hi Girls
I am catholic; however, both of my maids of honor are Greek. One of them is pregnant and is due May 18th....my wedding is June 28th. Its her first baby and im sure she will give birth later than expected.
Anyway...the other day she told me that she might not be able to come to the wedding because of the 40 day rule. Now, I know that the baby is not supposed to leave the house before 40 days and the blessing at church....but her mother in law is superstitious and is telling her that she cannot leave the house either before 40 days.....
My friend is telling me that she is totally going to be induced so that she can be at my wedding...if that doesnt work then she wont be able to make it.
Ok...Im all about tradition, but im upset. How am i supposed to wait until a month before my wedding to know who my maid of honor is for sure? Yes i have another one, but that's not the point. What do I say to her? What do I do? Please help me :(

sorry this is definitely a hard one , i don't know what you can say to her but maybe just sit her down and tell her nicely that if theres anyway she can let you know sooner...the shower will need to be thrown and a moh needs to be involved, and also its not fair to the other girl to tell her just a month before that now she has the responsibility of being moh

good luck