I am still trying to estimate the technology level of the inhabitants in the preserve. They have iron tools (and clothes fashion) comparable to 19th century Earth. On the other hand, the houses (glass windows in particular), and Uncle John's farm silo look more modern.
The windmill is obviously Alice's project, and not reflecting the general technology level. Electricity appears not to be currently used, but Alice may plan to improve health care by providing the hospital with electricity from the windmill. Also, she may have access to medicines and technology from the Outside.
The Night Walker appears to confine and isolate all existing nanotech in the Preserve (except Gavia, and Alice's own nanotech, of course). This may be Alice's work, and is also the reason why Alice needs to keep close watch on Gavia. Alice is obviously afraid of nanotech getting out of control.
As for nanotech in general, there must be an energy source somewhere (unless our basic physical laws are flawed). As this is technology indistinguishable from magic for us, I would not speculate too much on this.
As for Alice's role, I am still favoring the "caretaker" theory, that she is there to take care of the inhabitants, without interfering more than necessary. The preserve may be a big sociology experiment, or a "zoo" to preserve a population of baseline humans.
EDIT: I would guess Alice herself is baseline human, but heavily augmented by nanotech. This would "explain" her invulnerability and longevity. She probably got this "job" thousands of years ago. She basically has good intentions, but it is also human nature to be a raving mad dictator if you get too powerful.
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