It means they’ve not yet built any new houses within that distance to her’s (it sort of implies the narrator expects they will one day)

In this sentence, “yet” means still or up to this point, emphasizing that the situation described remains unchanged. Breakdown: "There are no other houses within a half a mile yet" suggests: Currently, within half a mile, there are no other houses. The word “yet” implies that this could change in the future (other houses might be built eventually). Common Usage: This use of “yet” is quite common, particularly in spoken or descriptive English. It’s often used to highlight an ongoing state or to suggest a future possibility. Examples: “She hasn’t arrived yet.” (She still hasn’t arrived, but she may soon.) “The train hasn’t left yet.” (It’s still here, but it will leave.) In your example, the speaker emphasizes the house’s isolation by noting there are currently no other houses nearby, but leaves room to imply this may not always be true. Summary: Meaning: Still/no change so far, possibly subject to future change. Common Usage: Yes, especially in informal speech and storytelling.

It means as there are not any houses that have been built in the area so far, but there could be in the future.

Agustin, the meaning as used here is “so far” or “up to now.” I think the sentence could be better written: There are no other houses yet within half a mile of hers.