Your baby looks adorable
. Please do not take her back until all her vaccines are given and it has at least been two weeks after they have been all given. Try and relax in the meantime. If there are any symtoms at of of illness be sure to take her to your vet . Do not wait until your little one gets too sick . She ought to be ok though.
I am certain that you are a a great human mom and love your pup dearly. I know how difficult it is to find the best food out there for your pup , and the healthiset. there are so many to choose from. My Suzi was also on Purina puppy Chow when I first brought her home.
Just take the Nutro back , and choose from the other two , and start her out slowly by mixing it with the old food. You do not want to upset her tummy .