For women, there's only so much muscle build up they can do, unless they are really dedicated to specifically working out for bowling.
I don't think its a crime to use a
wrist brace. I use a pro form positioner, its not a totally inflexible brace. I can bowl without it, but its presence reminds me to keep my wrist firm and not start doing funny things with it that will lead to inconsistencies.
I think probably in your wife's case she's not interested in working out at the gym doing arm exercises and wrist curls. She probably wants to enjoy the sport at a level the is somewhat competative but yet mostly social with you. Am I guessing right? So a brace might be a good idea. I wouldn't try any of the plastic bionic braces. A pro form positioner like I have goes down past the wrist and lends some support. One tip I use....the bar inside comes out. Its straight. But you can bend it (shhhhhhh don't tell anyone) to a slightly cupped position.
Erin