No dairy products ever, though they would love it it causes diarrhea and can dehydrate then as it may last several days. The diarrhea can stress the ferrets system and cause secondary infections or issues during that short time especially in a kit.
Moms natural wearing of the kits is eternal 5 and 6 weeks where the pups start eating moms food, but it has to be smaller pieces or moistened kibble, that’s also how you will be making sure they will get enough water in their system. If you do feed kibble food the minimum of 34% protein needs to be there from meat base not just plant. Food also needs to have Taurine in it, or if you feed raw or cooked meats it needs to be added in. This will help your ferret stay healthier and live longer having less health issues.
Pups need to eat about every 4 hours max. When they are first weaned baby ferrets are fed ground chicken, turkey or even 'pinky' mice; or they start on commercial wet kibble - softened sort and digest it easier. Starting them on raw meats will enable them to eat a variety of meats when they get older it they must be introduced to it and know it from weaning on. This should be fed about 3 weeks after their weaning age then you could switch over to the commercial kibble, or start cooking the chicken, they can be fed then a combination of meats cooked or raw and kibble to balance their diet. Be sure not to leave the food sit until it’s all gone as it spoils quickly (not minutes) and be sure to was the dish out immediately after to ensure o spread of bacteria that can make them sick. Same for thei water dishes, wash daily. We preferred ceramic or glazed dishes over plastic, metal too. Plastic may become a favorite chew toy and get teeth marks, scratches etc I them holding bacteria unless you sanitize between uses.
Just a reminder, ferrets pretty much imprint at their weaning stage, whatever foods or treats they do not try ow good luck trying to introduce them later on, if they were not learned as a pup the majority of them will refuse to try past a sniff.
Avoid foods that are high in complex carbohydrates, such as fruits, vegetables, dairy, or anything containing sugar. Because ferets are strict carnivores, their digestive tracts cannot process these types of food. They have a high metabolism and need to be fed 8 to 10 times a day as adults. The commercial food is good for their teeth in combination with their raw or cooked meats.
If for any reason you cannot find ferret food then kitten chow, (not cat as kitten is higher in protein) grain free with meat like chicken, lamb, turkey, etc listed as the first ingredients can be used in a pinch but you have to add fatty acid supplement which you an get at a pet store.
Hope this helps.
You can also look up how to wean your baby ferrets, what to feed them etc on line, they have some great information available.