As someone with thin wrists, I can tell you it would be extremely uncomfortable. Whenever I wore bangles, I was paranoid of them falling off. And large bracelets with clasps are even worse, because the clasps are usually cheap unless it's very good quality. I'm sure in the story, it's decent or good quality but all I can think of is the amount of times I've bumped my wrist against something and almost lost a bracelet because of the clasp failing. My job doesn't allow bracelets, so I don't wear them as much anymore but yes, there are so many issues with bracelets that most people don't consider.
That said, I would prefer a bracelet over any other form of jewelry except anklets. Having taken self defense classes, I can't really look at piercings and necklaces the same. Bracelets and anklets are at least practical and aren't likely to damage you in a fight. Plus, smashing that large bangle/bracelet in someone's face will at least do some damage. If they get ripped off, they aren't as painful as piercings and aren't likely to choke you like a necklace. So, I ignore the large size and just focus on, "At least she can break someone's nose with his gift."
I dont know if anyone has said anything about this---it aggravates me every time I see it--her bracelet is entirely too large for her little wrist. Every time I see it, I think, "It's gonna fall off!" She wears it bc Zepon bought it for her. I get it, but the artist or editor or somebody should've recognized that it was too large and resized it. It takes me out of the SL Every time I see it. Maybe it's meant to be exaggerated. I mean, the hair is exaggeratedly long, whether it's up or down. Maybe the bracelet is to be the same: exaggerated. But you can't tell me she wears it comfortably bc there's no way it stays on her wrist.