I would also get yourself come Nutri-Cal and supplement 2-3 times a day to ensure she is getting all the nutrients. You must be very aware that Hypoglycemia can set in very quickly with a pup that small. They do sleep alot and the nice folks on this site reassured me of that. Our breeder required a Vet check within 72 hours of our picking her up. Take in a stool sample to make sure you did not bring home any parasites.
We are enjoying a 13 week old. She is sound asleep and I write but I just want to pick her up and hug and play with her.
Good luck with you new little one. Welcome to YT. Everyone on this site loves to see pictures of your new little furbaby!