Magpul CTR with optional 0.7" enhanced rubber butt-pad on my Colt 6721
My wife doesn't want her own AR yet but with the several different stocks that I have her favorite to use is my Magpul CTR with the optional enhanced rubber butt-pad.
My other stocks which she doesn't prefer are Vltor EMOD, Modstock, MOE, Colt/ LMT M4, and fixed A2, out of these my favorite is my EMOD.
If my wife is going to have an AR for herself she would probably like a lightweight carbine with the CTR version stock that she likes, she also had tried my M4gery LMT carbine but it was still a little too heavy for her that's why a lightweight type would probably be the better choice.