I couldn't agree more with what the others before me have said.

It seems so childish to act like that, who cares what breed she is, if she's working out for you than that is all that matters.

I especially can not believe it due to the simple fact that she was a rescue. When you adopt a dog (unless there is paperwork from the previous owner) there is never a garantee about what breed(s) may be in a dog.

If your mother does return her for some reason she better get her next dog from a reputable breeder so she can have her purbred dog and not go through all of this again.

I feel bad for the poor pup. I'm glad she doesn't understand what conversations are going on. It would break her poor heart if she knew that your mom cared so much about a purbred dogs (even though she does appear to be purbred).