The only advice i will give you is dont chastise the ferret for biting, feed plenty , more than the ferret can eat in one sitting , in other words if theres some food left over after each meal then your feeding enough.
These kits here are around 7 weeks old & have teeth & know how to use them , they are having 3 meat meals a day & they are also having a small dish of dry food down all the time , something i dont normally use but i suspect they had been offered it previously as they clean the dish everyday
Also handle after a meat meal , when there bellys are full , far les