So, she still needs to gain then, do I have that correct? If yes, then keep her eating what she *will* eat, for now. Another option is to take that Ceasar's and mix in some better-quality food with it. Make sure the Caesers you're giving her is Puppy formula, esp if you're going to 'cut' the Ceasars with another food (if the 2nd food is adult).
If this works, then you could eventually try adding less and less Ceasars over time. Another thing to try later, when there is less Ceas, is to sprinkle the food w/ Parmesan cheese as it's nice and pungent and dogs seem to like it.
I think it's pretty cute how she worships the poodle
.