I get that it's frustrating that she just didn't tell you directly that she would be working, but I would never plan my birth around someone else's schedule. It would be nice of her to help, but ultimately it's not her responsibility at all. Sounds like if you are desperate for the help, that you'll need to find some other way to make it work that is convenient for her, ask another family member, or hire someone. She sounds like a flake, and I would def take this as a lesson learned that maybe you shouldn't count on her.
nycnola: he doesn't believe in God. So....maybe not the best Godfather? Again, shouldn't become an issue, but BIL is gay and I KNOW she will make it about that, even though we pretty much just require our Godparents to at least believe in God, and I am seriously thinking she told BIL about her wishes so now we might hurt BIL's feelings, too. Oh MIL. I love her, I do, but I am SO FRUSTRATED!
I'm a little confused about this part of your post. Are you saying MIL would accuse you of not letting BIL be the godfather because he is gay? I would think her opinion of you is pretty low if she thinks his sexual orientation would prevent you from choosing him as the godfather. I would be furious if someone accused me of being a bigot, which is, essentially, what I think your implying