When I broke my wrist last year I couldn't open jars or do much at all - broke left wrist (both radius and ulna) and sprained right wrist in the one fall, so both hands were somewhat useless for a while there. If your mum is doing things herself that's good, let her do as much as she wants.....it will make physiotherapy easier when the cast comes off, because by gosh the wrist which is broken will be stiff for a while.

Cheers
JennieG