It sounds like she might have an easier time getting into and out of a crossover or at least a somewhat higher than average car.
Among BMWs, I'd suggest the 3-Series GT. The driving position is lower than in a crossover but significantly higher than in a 5-series. It's a hatchback with an especially roomy rear seat. Very handy.
The Infiniti QX50 is an aging design, and somewhat tight inside, but received more rear legroom for 2016 thanks to a wheelbase extension and could be something she'd like. The 2015 (which some dealers might still have) had a tighter rear seat and rode an inch lower (I preferred the slightly lower ride height).
Among Lexus, possibly the new-for-2015 NX crossover rather than the GS.
I'd like to recommend the Lincoln MKC, as I really enjoyed driving one for a week, but first-year reliability has been poor.
Finally, the Volvo XC60 crossover is worth a look. Reliability is a little iffy, as model years before 2013 don't look good in our stats, but it was among my wife's favorites.