Also I dont think its a good idea breeding her because didnt her sister have a funny shaped head and you thought there might be something wrong?
This could well be something that the mother or father passed onto the babies and your pup could still be a carrier.
Did your breeder ever find out what was wrong with the other pup?
I know how you feel about the spaying though... I will cry when I have to take Poppy but I too think we are more bothered about it then our babies are