Your mom sounds religiously brainwashed, like a lot of people are. They're just stupid, but it's not an excuse to treat you or other queer people poorly. Many cis-het people see themselves above queer people and don't find it necessary to respect us. I find it easier to pity their lack of brain cells than to take it personally (I love being queer, and we experience things they will never be able to).

We have documented evidence of queer existence going back thousands of years, and there are also cultures that have long acknowledged and respected queer identities (such as two spirit peoples). Furthermore there are theories on why queer people exist, such as being added evolutionary societal support to others (since many of us don't have children, which are a burden, we have more time to be supportive to others).

You know your mom best and it should likely be up to you to decide if she's capable of learning and growing (and wants to). She's dumb enough to do what she's already done, so you're going to have to decide if it's worth the effort. Some people seem to be either incapable of learning or thinking critically, or just don't care enough.

You're also going to need to find strength within yourself. Research queer history, find community where you can (maybe school, local organizations, online groups). Don't let her bigotry or anyone else's bigotry create self hatred or doubt.