High protein doesn't equal soft stool, for instance on Orijen usually the stool can almost appear a little wet but is still a solid form. The stool will look healthy.
2 Cups a day wouldn't hurt anything like PK was saying but i'd just keep an eye on growth, with the feed your switching to you may not need to feed quite that much for the same result. If you want to feed 2 cups for a few weeks and see how it goes, if you feel you are feeding too much and your pup becomes a little butter ball cut back slightly, after all that butter ball will keep growing into her body.
"It takes courage to grow up and become who you really are" - Cummings
"If think you can't, you're right. If think you can, you're right." - Hatton