I don't think it is anything you did. She may have ear mites with an ear infection. So she would need an antibiotic with her ear med. It is very common in puppies. Seems like all of my and my parents pups included ear mites when we got them.
Give her extra attention and if her ears are bothering her take her in on Monday.
Also, you should try some nutical or some kind of vitamin paste to perk her up. It really works good as I have seen.
She is sleeping in because she does not feel well. If I were you I would ask the breeder if the ear med she gave you includes and antibiotic. If it is over the counter it does not so see your vet on Monday.
Poor little Cherry hope she is feeling herself soon.
