Holly
The woman is obviously an idiot and caught up in some cultural belief that doesn't have anything to do with the christian doctrines but some ridiculous 1950s ideology.
You poor love to have had to sit through her rant. Understand her for what she is and try to move past it.
I like the sound of your MIL(and other in-laws) who showed compassion in her response to your distress.
Hugs to you hun.

dusty