If you are out bike shopping/test riding, have her try out:
Giant Suede
Trek Pure
Electra Townie

They all have the pedals forward which lets you sit upright, touch your feet to the ground easily, and have good powering in your legs. I ride a Giant Suede with 7 speeds and love it. It looks like a cross between a cruiser and a mountain bike. I ride through gravel, dirt, sand, & mostly pavement without problems. My hip and neck bother me at times from a fall years ago, but bike riding seems to keep me loosened up and feeling balanced. I'm approaching 60 and feel great riding 4-5 times per week.