Make her install Gentoo in her own and make sure to berate her at every step /s

Personally I would go with something that has KDE so she gets fancy animations and stuff, but Mint is a perfectly valid choice too (cinnamon also has some cool stuff to toy around with but not as much imo). Just make sure to show her how to install stuff, and put adblockers and shit in the browser. Also highly recommend installing some of the linux games.

You bring on some interesting points and I will definitely read your comments. Thank you.

Do it. Gaming was the only reason preventing me from switching to the Linux side, until Itried and found out that literally every one of my games work on Linux, sometimes even better than on windows.