Well, my mom is the same way with me and religion. In 2006, we had a "blip" in our relationship, which began when she used my brother to communicate to me her disapproval. I was totally blindsided, and didn't even have the presence of mind to write a response letter for a week after it all started.
In the letter, among other things, I asked her if she wanted a relationship of full honesty in which she would know all of who I am, or if she only wants me to say what she wants to hear. She never answered my letter; when we spoke again it was as if nothing had transpired, and when I asked for her thoughts she said she wasn't ready to talk about it. It never was discussed.
Your mom might be in a similar place right now. My suggestion would be to come right out and ask her. Tell her you're thankful for her support, and that you'd really like an opportunity to learn her thoughts and feelings, and to share yours. Ask her when you two can get together for this.
If she stalls or flat out denies your request, just respect that space she's in, and be thankful for her love. Best wishes,
~Valerie