The best way to do it is to set up a colony and never change it. Don't take the male out and never change the females around. Very often once separated, you won't be able to put them back together again without them fighting.
It is common for everyone in the colony to help with raising the babies including the dad. They may pile them all up together or put them in several smaller piles. Don't worry about it, they will get around to everyone and feed everyone.
If I get a litter of pinkies in a colony where I already have a lot of larger babies, I may harvest the pinkies because they are likely to be smothered by their cousins. If I get too many at once in one group I may harvest some of them just to take pressure off the females. I have enough snakes that I need mice of all sizes. I understand that not everyone has that option. If you don’t, make sure your cages are big enough to handle the male, all the females, and 15 near weanling size babies from each female. The day will come when you will have that many at once.
