This is what the vet told me, let me see if I can explain it to you... if you dont understand it tell me and I'll try again ok? With the tip of your index finger and the thumb make a circle and maesure the crown of your tinys head. That is the aproximate amount of food you should give her. Her stomach is very small and if you feed her more than you should she could go into vomiting. Maybee after you do this and try the amount you could measure it in a cup and see how much you should feed her as she is growing up. She should eat three times a day and keep dry food and fresh water ALWAYS available for her, you can also give her treats. The water should be everywhere... Also you should have some honey handy in case she doesnt eat well, give her about 1ml that will keep her sugar stable.
Hope this helps!!!