breeding pedigre & Mongrels

does anybody know if you breed a pedigree witha mongrel if the pedigre has any more litters will they be mongrels?
i have got a pedigre king charles spaniel and a labrador crossed with a staffy has mated with her by jumpin over fence and shes had puppies being the mongrels. will this affect her other litters if shes mated with another king charles spaniel

Your Dog’s REAL Age Isn’t What You Think It Is

If you’d like to find out how old your dog really is in human years (and why it’s important): Click here to learn more »