DarkCrisis
Let her cook.
I've suggested AD&D. The other old timer in the group (a dad of some of the teens) actually requested it. My wife is balking at it because of the lesser power and thinks it's going to be difficult to learn.
I find it no more complicated. 5th ed has a tons of feats and special abilties and sub classes etc etc etc You have to keep track of skill checks and who has advantage etc. It's not less complicted its just as complicated in a different way.
People like to dump on THAC0 but you can just use a chart? I just convert it in my head to ascending AC when I play AD&D. 3 AC is like 17 AC. THAC0 is 18 thats a +2 to hit. Easy..
Hell you want real easy? Play Basic/BECMI/Rules Cyclopedia.
Use a Retro Clone that converts it for you to ascending AC. Like Old School Essentials. There are others out there as well.
If the only thing holding people back is "different rules and ascending AC" Retro Clones fix all of that and keep things even "more" simple.