Poor sweet little precious girl
!!! BLESS your heart for taking her in and giving this kiddo some much needed TLC
. Thank god someone reported her!
In addition to feeding puppy food, I would be giving calorie dense treats like little pieces of cheese and little chunks of peanut butter off of my finger - both of these are small, calorie dense foods. Might also want to scramble some eggs and give her some egg here or there too - it should be an easy protein for her to digest.
What about giving some chew treats too, to clean up her teeth etc?