PS I have also said I won't be allowing my child online in certain public lobbies, maybe you should limit her use (Unless she is having good experiences obviously).
My dd is 11, and is a bigger gamer than I was at her age, (I started on a Amstrad haha) as she's getting older her taste in games changes, and I have been thinking a lot lately about to deal if/when she gets sexual comments. I'd feel uncomfortable telling she can't play a b or c because of men/boys making sexual comments to her as it feels a bit victim blamish to me. It's also making her adjust her behaviour when she's done nothing wrong if that makes sense?
It's something we've had to talk about as one of her friends are starting to experience street harassment, and she's had a discussion at school about it etc, she's expecting sexual comments at some point as she feels that if (some) men are comfortable telling an 11 year old school girl to get her tits out in the street then they be comfortable doing it online and may be even worse as they have more anonymity, she has said that they know that as doing it in the street isn't taken seriously, why would they think it would be taken seriously in bra game.
She has said that she won't ever stop playing games because she as as much right to be in that online space as males and it does not exclusively belong to them. That it's massively unfair that many people think the way to stop sexual harassment towards females, is for the females to limit their activities instead of telling males to not sexually harass.
I monitor her online and she mostly plays with real life mates, both male and female and at the moment they all treat each other as equals and are respectful of each other. She's been on minecraft servers, splatoon and Pvz under supervision and there's been no hostility towards her but that could be because she plays on her dad's account, so looks like she's 40 odd year old male.
I was going to list my own experiences but don't want to post a massive wall of text. I will say though that I'm well aware that it's a minority of men/boys doing it, but it's a big enough minority to have stopped me playing online with unknown males, I don't tar all gamers with the same brush, and don't hate the gaming community, but just like I don't know if the unknown male approaching me in the street is going to be like one of the few who have make sexual comments or physically attacked me, I don't know if the male who joins my games is going to be the same, so I just don't engage with any, which I annoy myself for as it limits what games I can play, and even pretending to be male doesn't always work as sometimes I need to speak.
Yes, some gamers are homophobic and racist too and I'd fully support any action started by the people who are affected by racism and homophobia in gaming to stamp that out too. Doesn't make the sexist shit less of an issue.