The studies that say that "Half of gamers are women" usually include casual or mobile-exclusive games as part of it. When you get to women who are actually, shall we say, "enthusiast gamers" the percentage does drop significantly. There is also something to be said about them, in general, preferring different games.

For instance, my fiance plays games so we have a shared passion, but we play VERY different games. I like strategy, poli-sim, city builders, shooters, and racing games. She prefers puzzle, casual (think stuff like Turbo Dismount), and life-sim games. Even for games we both like (Fallout and Elder Scrolls), we play different. I prefer a challenge, I like building my kit and fighting style, I like the gameplay, and I like having to manage my supplies and inventory. She likes turning on God Mode and using the fact that she has infinite health and money to dick around, as well as experience the story without having to worry about if she has enough supplies to defeat a Deathclaw without it punching her in the face.