Hard to say because everyone is different, but I think you're on the right track. More curved fingerboards (like the old 7.25" Fender radius) tend to be better for chordal stuff which I reckon is one of the reasons a lot of rhythm/chordal players tend to like old Teles, Jags and Jazzmasters. If she has small hands scale length could be important too. 24" guitars can be much easier to play in that respect. I'd suggest she should have a play of a Mustang - 7.25" radius, 24" scale, small body, cool as all hell too. Could be right up her alley.
Crustaceo ergo sum