I would go about it like this:
Day one to three: 1/8 cup Fromm and 1/3 cup Iams for the two feedings, and the last feeding do 1/8 c of each. Do this for about 3 days.
Day four and five: 1/4c of each for the two early feedings, then 1/8 c each for the late feeding
Day 6-7 (or until you run out of Iams): 1/8 c Iams and 1/3 cup Fromm for the two feedings, and then just Fromm for the evening feeding.
Once you are out of Iams you puppy will be bigger I am sure and need more food. So slowly increase the amount of Fromm as she grows. When she is a 'teenager' (about 6-10 months) you can give about 1 1/4 to 1 1/2 cups twice a day, and once she reaches age one you can start to decrease her intake depending on her weight and activity. My girls get 3/4 cup twice a day (the ones over a year) and the pups get 1 cup twice a day now that they are almost 1 year old. But they also get many treats and such throughout the day too.