has you're mom ever talked about gays? if so how did she stand on the issue? if she never really did talk about it then just how open has she been with being okay with other ideas that aren't her "life style"? if all else fails just "happen" to bring up a topic about gays and listen to what she has to say. the longer you can drag it on the better the information you will probably get.
yea i think i'm going to bring something up on gay people because with my mom the topic never comes up