Unsurprising that she would die of 'dysentery' shortly after 'rescue'. Most water supplies in that day were contaminated with some small percentage of sewage. Infants in the area either died or adapted. Adults were immune to the established level of pollution.

Juana Maria, living well away from humans, and completely innocent to regular low-level exposure to human waste, was immunologically unprepared to deal with it.

The bone and iron hoop knifes are instructive of how effective even a simple, low-tech tool can be. Given a wonder alloy modern knife she would have recognized the advantages. But pig iron and bone work far better than no knife.