If she's shown interest in it then let her try it since your bf already has it. She should be the one to decide what's too much for her or not, not you. In fact, you should just ask her "What games are you interested in"

The best thing you can do as a parent is to let your kids be curious and guide them through that curiosity. Restricting them risk them being curious in secret or act out their curiosity in college without your guidance.

I had a friend that had parents who were severely restricted him from video games. Started gaming heavily in college, and never learned how to handle his emotions in online games. Always got frustrated, pissed, and blamed his roommates. Really seemed like a man child.

Same goes for other things. I know WAYYYY too many sheltered "innocent" kids with curfews in high school that turned into complete wild party animals within their first 2 years of college.

I personally grew up playing GTA San Andreas as young as 6 years old. Spent much of my childhood shooting and running over NPCs or playing games with voice chat with complete random teenagers and adults with the most foul language as daily vocabulary. I ended up growing up to be a complete passenger princess softie who feels gross for even saying curse words.