You got good advice. You'll be able to tell when they are going to pop. I've been able to tell within a day when every single one of my moms is going to go. I do spent a lot of times with my rats though. I want friendly rats for safer snake food. As long as you spend time with your rats and keep them pet friendly you can move babies and mom to a new tub. If mom isn't nice, be very careful! Rats bite hard and can split you open pretty good.
The moms literally look comical. They are pear shaped with swollen teats and when they are walking look like they swallowed a tennis ball. They will also start nesting up their bedding. I would also recommend treating pregnant rats and moms to table scraps. Mine get all sorts of tasty table scraps, bread ends, stale crackers, chicken, and treats. It really helps keep her and the babies more healthy. The treats also build up some trust. After a week or two you should probably feed off any rat pups over about 8 in the litter. This will also ensure healthy mom and babies.
An added benefit to putting the moms in seperate tubs is that your babies will be healthier if she isn't pregnant while she's nursing them. If you don't give them a break you will have less healthy babies and burn the moms out very quickly. Seperation into their own tubs gives them time off before starting the process again. I believe that healthier rats equals healthier snakes so that's why I got breeding my own.
Regards,
B