You can't change people. People have to be willing to change themselves. Trying to convince people, persuade them, re-educate them rarely, if ever, works, and only makes them defend their stance more, which triggers the wrong cycle.
Your mom has her opinion, rightly or wrongly, as you do & she may will disagree with you as much as you with her. She has her reasons for her opinion, whatever they are, as you have yours.
I think the hardship for you is that it is your mom, and not just anyone. And it is hard for a tolerant person to know that a dear one is prejudiced. From anybody else, you can avoid their company, but it is hard to do that with your own mother.
What I have done (or tried to do, rather) with fmaily with whom I actively disagree on sensitive issues, and family I cannot avoid is to establish the rule with them that "Look, you have your opinion which I know, I have mine which you know. We obviously disagree on this point. Let's not argue about it. Just please don't broach the subject in my presence, or hearing range if possible, because we know we will disagree." That works 95% of the time. If it comes up in my presence, I just get up and leave the room, if asked why, I tell them they know, and ask them to call me when they are through talking about a hated & hateful subject. Over time, the subject hardly comes up.