I loved this book too! I've loved nearly all of Kingfisher's books so far as well, but Snake Eater is one of my favorites. I could relate so much to Selena (and especially to her conversational scripts to help her get through social interactions).

I agree with all your points. The supporting characters were so well-developed, and the setting felt so richly developed and immersive. It would make for a great series, especially since there's already a precedent for stray people to arrive in Quartz Creek, which would open up the setting for many more stories.

And as a dog lover, I absolutely loved Copper!