Any experience with dogs formerly used for breeding?

We adopted a beautiful Golden Retriever from a local rescue organization. We were advised she was surrendered by a breeder that had used her as such for 6 years and may have been in a less than ideal situation during that time. She is very sweet and docile. In the last three months she has been surrendered from her home of 6 years, been in two foster homes, spayed and treated for eye, ear, and skin infections and then adopted by us. We have had her only 10 days and are aware that is a long road ahead until she adjusts to the comforts of being a loved family member.
She came with a small stuffed bear to which she is very attached. We gave her two small toys to provide her with other play choices. She treats all of them as if they are her puppies. She stays around them almost constantly. She has placed them on the dog bed we got her while she sleeps on the floor next to them If we move the bed to be nearer to us, she goes to get her "pups" to put on it.
We would not care so much about the behavior except she hides away with her pups rather than interact. She has adjusted to her new name, she will come if called, enjoys her long morning and afternoon walks, loves to be brushed, but as soon as finished she retreats back to the dark bedroom to be with the pups. She doesn't know how to play but feel we can deal with that later.
Wondered if any others have had such an experience as adopter of a dog used to being a mother and if so, have any words of wisdom.