Has she got Shimano shifters?

Tell her to check out some bikes with SRAM or campy (and try the different models as well). They are smaller sized in the grip and the brake lever is flatter and not so rounded and might suit her hands better.

I have short fingers and large palms and find I cannot wrap my hands sround the shifters to reach the brakes. I use interupt brakes at the moment but realise a permanent solution would be to change the shifters after trying them in the shop (and other people's bikes) and finding those better.