As suggested above, the testride removed all doubts, her body language said everything. It was the "little things" that made a big difference, such as the throw of the brake levers being shorter was a big deal as she's often finding her forearms tired from braking on descents (I think she's experiencing that MotoGP phenomenon of "arm pump"), the narrow width of the handlebars, the shorter reach. Tubeless tyres is a nice bonus, it'll probably encourage me to switch.
I did not want to like this LIV bike as I'm not a big fan of GIANT - just for me, the big manufacturers are a bit "soulless" - but there's no denying the "bang for the buck" value, and most importantly all the women-specific features, which she immediately noticed on the testride, that make this such a comfortable option.