My best friend doesn't see me how I am and somehow that's worse than her not knowing

For context: I'm a transman. I confessed to my best friend of like 7 years a few days ago via text. She immediately accepted it and told me it wasn't a deal for her as long as I'm happy.

Now the twist: we went swimming today, the first time we actually met face to face since I told her. The topic came up once or twice. And even when she seems understanding, she keeps calling me "girl" and hints that I'm still a woman to her until i chnage medically.

Asking her directly seems a little rude, she accepts me after all and I feel like that's the best i can expect, I don't wanna come off as confrontational or smth.

Does anyone have experience with similar stuff and how would you handle it?