Tim, just a suggestion,........if I were you , I would contact 4 or 5 different
breeders. Email them, call them whatever suits you. You can see a number of different breeders on such websites as Qualitydogs.com to name only one.
Then see what all of them suggest. Email them pictures and tell them what you have posted here. I have found breeders of most breeds of dogs to be very helpful even though they didn't sell you your dog/pup.

I know from experience the better the dog food the more nutrition that the dog or puppy absorbs, therefore less stinky poop and less poop all together.
I have a large breed dog and have always had a large breed dog, he now weighs 75 lbs and only eats 2 cups to 2 3/4 cups per day. BUT, when he was in his growing stage between 3-6 months he was consuming, at times, 5 cups a day, I didn't know where he put it all, he was fed 3 times daily. But on the average, during that big growing stage he did eat around 4 cups a day, give or take a few ounces and his "output" was not even imaginable compared to what he ate at the time. He has been on Canidae for a long time now. Less output, uses more nutrition and healthy as a horse.

I agree with the previous posters from experience that most vets don't know all that much about nutrition unless they specialized in that additional field and yes, my vet too reccomended Science Diet too and I never took that recommendation. Vets who sell this also get some kind of compensation for it but that's not why I didn't use it. Anyway, that's just my input for whatever it's worth but I would contact some breeders and ask them what they feed, how should your dog look/appear and tell them what you are feeding her.