My parents aren't hateful but misinformed about my trans girlfriend. It's putting a dent in our relationship
So my (cisF) girlfriend (MtF) of around six months has been slowly meeting my family. Both of my parents were raised conservative and Christian, and I told them she was trans shortly after I found out (a couple months into our relationship).
My parents are not and have never been bigoted. The takeaway that they had from our conversations was that as long as I was happy they'd be supportive, and have been kind to and spoken highly of my girlfriend, inviting her over and always wanting to know about her. However, my mom keeps misgendering her and appears to think what I mean by a "trans woman" is that she's a more feminine man. She occasionally still asks me if my gf is "still a woman" as if it's a passing phase. I get the sense she's genuinely confused more than anything. My dad is slightly more woke but similar; it's harder to get a read on him, but he tends to avoid using pronouns for her in general or skirt around the subject. I've tried to shield my girlfriend from the misgendering and spoken about her in vague terms to avoid conflict but it's starting to break down. I get the sense they are genuinely putting in effort to learn and be respectful but I wonder if I'm asking too much of them.
My family means absolutely everything to me, especially my mom - she has been my best friend for my whole life, and she would never, ever be the type to discriminate against someone or think of them as lesser for their identity. But it has understandably taken a bit of a toll on my gf to feel like she'll never be truly accepted for who she is by my family. I just want everyone to get along. Any advice/similar experiences?