Guitar buying advice?

Hi y’all
As some of you know I’m a bluegrass banjo player. I’m not very good, but I enjoy it and I’m in a band. I have a Martin D-18 clone guitar that I picked up used at a bluegrass festival but the action is kind of high and it’s a dreadnought style which has that wide body. I play it from time to time when needed.

My wife, out of the blue, told me she’d like to take guitar lessons. My Martin is a little hard to play if you don’t have a pick so I’d like something smaller with lighter action that she can strum and learn chords. (I am not going to teach her—I have a guitar teacher in mind). I’m thinking of something like a ¾ Yamaha. Guitar Center sells one for about a hundred bucks or so, but I don’t know how good it is. I can spend more if I need to. I just want something that is easy to learn and play.

Any ideas?