Congrats on your pup!!
To me she looks more like 4-5 months - my own pup Lucy looked very much like your pup when we got her & she was aprox 5mths (she's a rescue so I dont know her exact age).
I would just say that the breeder is wrong telling you that your dog is pedigree is she gave you no paperwork & because the mother is not KC registered. Your dog is a purebred, meaning from 2 parents of the same breed.
Did the breeder microchip your pup? Breeders in Ireland (I believe) are required to do this before you take the pup. If not this should be done when you take her to the vets for her vaccinations.
When I got my first Cav pup he had had a parvo cav from the breeder but nothing else & when I rand my vet they advised me I should have him a few days before bringing him in for his vaccinations (unless I was worried about him).