Is she used to riding with narrow handlebars? I'm a petite rider and when my Specialized road bike came with 38cm handlebars I didn't like them. Too narrow. I switched out to 40cm bars (Salsa Pocos). I went even wider on my touring bike, with 42cm bars for better stability on a loaded bike.

I may still have the 38cm bars around (was trying to sell them). They are 31.8 clamp size though.