How can girls play online games?What do boys say to girls in games?

Since you can't control what other people say the one thing that is worth putting effort into is making sure you don't get a chip on your shoulder because you've encountered some morons online. 

I've verbally abused women before because they were selfish, toxic players.  Doubtless they thought being female was something to do with it, but it wasn't.

If someone wants to verbally abuse you they'll usually just go for the lowest hanging fruit in terms of obvious insults.  Insults categorised by sex are a pretty readymade option for folk who aren't the most flexible thinkers.

Just concentrate on playing in a way that causes people to be less likely to abuse you, mute the ones who do or argue back with them.  It has ever been thus whether you're XX or XY.