You got your answer right away from @mknowles16 !
Finding a comfortable neck shape and body style are really important and the only way to discover what’s comfortable for your wife is for her to play a bunch of different guitars. If the guitar isn’t comfortable for her to play, the name on the headstock will be poor consolation. My previous guitar was a Martin and it was great but take care that your like for Martins doesn’t get in the way of her finding the guitar that works best for her! And keep in mind that there are many good guitar tones, just like there are many good audio system sounds.