Well if that's what the breeder was feeding her, I don't even want to go near looking at your pup's pedigree
I would seriously think about changing foods about now. Pup has been home long enough. If you like mixing wet with dry there are a few good quality wet foods.... I believe Wainwrights wet is supposed to be good (from Pets At Home), along with Nature diet and Nature's harvest? (That right everyone?)
Dry wise you should be looking at grain free foods. Cereals are not part of a dog's natural diet, they're just used as a cheap filler and cheap source of energy. It actually puts quite a bit of strain on your dogs digestive system.
What dry food is it? You said similar to Hills so I'm assuming it's not? lol.
Dry wise you should be looking at foods like:
Orijen
James Wellbeloved Turkey & Veg (Not any of the ones with rice)
Fish4Dogs
Acana
Applaws
Barking Heads Salmon & Potato
If your pup isn't finishing her meals then her tummy is probably just full

Has she been wormed? They are supposed to be wormed every 2 weeks until 12 weeks (I think it's 12 weeks isn't it?) Breeders either start at 2 or 3 weeks of age. Hopefully your breeder has wormed the bitch during pregnancy as well as after they were born too.
Maybe add one more meal per day and cut down the size. She'll tell you herself when she's ready to cut down on meal times.