Hey Joe,
I'm so sorry things are uncomfortable right now. It does sound like your mom isn't too pleased with the situation, but it's a very good sign that she approached it in (from her point of view at least) a warm, loving way. It sounds like she's pretty religious, but not in an agressive, malevolent way. So it may just end up being one of those things that you guys always disagree on. However, the other are right; with time and more information she may begin to move toward acceptance.
If I were you, and this is just purely how I would react, I would be very nice and friendly around her, but not really bring "it" up. Like don't avoid her, but don't shove that aspect in her face either. If she brings it up I'd try to be open to the conversation, pay attention to and listen to what she has to say...but be unyielding in your views. Also I'd stress that you're happy, everything's fine, and there's nothing to fix. Of course that's all just my opinion and you'll have to do what's best for you.
I wish you the best, Joe. We're all here for you, and if you need to talk or anything you know where to find me Take care
Kevin