I do not believe you can
get those suggestions at this time. Maybe if the kittens were three or four months old you could consider socializing the mother cat but not now. At that age the kittens are becoming much more independant of mom.
At this point all she cares about
is protecting her kittens. She is not interested in making new friends. It just is not feasible.
She will do whatever she has to to make sure her babies are safe. If that means taking on a Golden Retriever she will do it, as you found out. She will most definitely go after any and all that come too close to her litter. She will die defending them. There are many stories of cats and dogs being seriously injured while trying to make friends with a nursing momma.