George,
Maybe re-looking at her bike fit would help? It might be possible to transfer some of the weight to her feet and saddle by shifting the saddle back in its seatpost. Of course, and assuming that her fit is correct now, you'd have to shorten her stem by the amount that the saddle shifted back. Or, if her current fit is a bit cramped, do nothing with the bars. Although she'll feel more stretched out, her balance point will actually be farther back.

Also, by moving back, her distance to the pedal will also have increased. You'll have to adjust the saddle height accordingly. This change will be small.

I may also be that she'll have to try to "hold" her torso more upright to unload the hands and wrists. You know that this is done by engaging core muscles and relaxing arm/wrist/hand muscles.

Have you had anyone look critically at her fit while riding?