
Hi Geenie
My girl had similar- Toy breed two pups born but one died and my single pup is 5 weeks old and a rascal- I do feel a bit sorry for her and so bought her a few cuddly toy surrogate sisters that she cuddles into and climbs all over.
Other than that she is chubby as has all the milk to herself and is outgoing as because she is an only one I can have her out around my feet with mum and my other bitch more easily.
Hopefully some people with more experience can give you hints and tips but I had been worried to and all is ok
Hope that helps
AM