I'd keep an eye on her, and also call the vet to schedule a first check-up, just to be safe, and get a relationship started with a good vet. The pup is still young, and settling down. If she's eating and pooping normally, that is a good thing. The behavior changes may just still be part of the adjustment period. What is she getting for food? And what for treats? Not having anything to eat for 6 hours isn't too much to worry about, has she "done her business" since then?