I separate pregger moms when they are ready to drop. When I first started out, I had a 1.2 in 10 gallon and everybody/somebody nommed down all the babies when one of the moms dropped.

Last fall, I left .2 in a 20L stay together as they were gonna drop within days of each other. As one mom took over both litters, it took FOREVER for the babies to mature because they weren't getting the same quantity of food as they would have if there less babies per mom.

So, I always separate and have great results. I keep my buck in a shoebox size kritter keeper and when I'm ready for a girlie to be pregnant, I pop her in with him. When she looks preggers, I pull her out and into her own shoebox kritter keeper. When those babies are ready to wean, I divide and put the boys in my male grow out enclosure and the girls and moms in the girl enclosure. Rinse repeat.

Granted I don't have many snakes to feed on mice (a cornsnake and when she wants a mouse, a bp), but I've got a crapton of mice in the freezer ready to eat. =)