I don't think you need to worry. Absolutely baby puppies are just like baby humans - they need to sleep a lot. Exactly how much rather varies with the individual, but pretty much all of them will be down for as many hours as they're up during the day. As long as she is happy, healthy and playful when she is awake, then I wouldn't be concerned about her.
As for the eating thing, most likely that is indeed a phase. Puppies can be notoriously picky eaters as they go through spurts of growth, followed by periods where their bodies don't need so much energy. Chances are, in a week or so, she'll be pretty keen on her food again - for a while

until the end of the growth spurt. Very much like human kids really.