My dog was bitten by a rotweiller and my dog is a poodle, and now she is sleeping all the time is something wrong with her

What did the vet say?

A dog bite needs to be seen by a vet. You may only see a small puncture wound but underneath could be a festering mess.
If your dog was shaken by the larger dog (not uncommon) then he could have suffered internal injuries.
Best to get your dog into the vet for a check.