Heh...we could argue the semantics of that all night rofl.
Just because it's never hinted there is only one, doesn't mean there's more. we can only go off what we are shown, and we are only shown 2 in the entire story. Veronica has one has a child...and Kane is left one. The one Otto brings to Nadia, prettty sure that's not Veronica's and we know Kane left his and didn't get it back.
The fact that from Kwame's words of
"It's a data bracelet used by The Karlsson Group. It's unlockable when you wear it near a specific secure access point matched to its signature. This one looks very high end in design. Very valuable." shows there are more in the world (but then we find that out later in the park flashback anyway), however, given what it is, we have not seen a single person wear one other than Veronica (as a child)
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and Kane when he finds his, points more to it being Kane's and not some random person (presumably important enough to have such an item) we've never seen with one. I've not spotted a single other bracelet in the story so far, either on someone or lying around.
The other side is, making assumptions, with no real evidence to back them up..to fit a narrative that also isn't even hinted at. So if it's a different one (go with it for now), we're assuming Otto/Someone else, managed to steal a data bracelet from a Karlsson sister (because I can't imagine anyone else being important enough have one....so
high end and valuable)....and if so, for what purpose?