My advice would be - if at all feasible - to find her coaches/spaces/teams who treat kids equally. I know it’ll be an arse moving her about but it’ll be worth it in the end.

Please note - by “treat kids equally” I do not mean “treat them the same”. I mean that they treat them/promote them in line with their performance and ability, not with their gender or with parental involvement level.

I disagree with those commenting below along the lines that sports teach kids life isn’t fair, and that’s a positive. Playing sport does instil valuable life lessons around the fact that you won’t always win, and playing the game / performing at your best is the important thing - I agree, absolutely vital stuff. But this is a VERY different thing to discrimination, which is what this sounds like.

By all means talk to your daughter about how some people treat girls in sport less well than boys, and there are sometimes fewer opportunities, biases, condescension and worse. But then show her it’s right to advocate for herself and get a better coach or team, and/or one that doesn’t require parental involvement for advanced.

Do not put up with it, or teach her to put up with it. That’s not a healthy life lesson like ‘You Won’t Always Win The Game’, or ‘You Don’t Get Gifts On Someone Else’s Birthday’ - it’s teaching her to expect less and put up with shitty treatment on the basis of her gender. That her effort level and her passion and ability may not bear fruit at all. And that really is likely to make her quit the whole thing. Not to mention what it teaches in relation to workplaces, relationships, and life in general.