My experience
1) As others have said - wider allows lower pressure and a more comfortable ride.
2) If the frame won't allow wider tires, consider going tubeless. I run 700x28 at 60psi on a road bike. Kind of a hassle to set up, but the ride quality is high. On a gravel conversion, I mounted some Donnelly tubeless on standard cheap rims without problems.
3) If she has carpel tunnel, try double wrapping your bars, and of course gloves with Gell padding.