I've started to hide my games. At the moment, the only games I have installed on my computer are Blockland, Terraria, Minecraft, Stepmania, and I've hidden Quake 3.
I'm going to stay committed to this until she either allows the games or I'm older. I know people will say "Wait unitl you're older" but why? The games don't affect me, I don't try to do the things I do in games in real life. It's not going to make a difference if I'm 11 or 20 when I play the games.