Hmmm, this is interesting:


Lactation normally lasts 3 weeks. It is a good idea to wean the litter and sex segregate them at this time. By continually supplying surrogate litters, a female's lactation can be extended up to 70 days.
From: http://www.ahc.umn.edu/rar/breeding.html

The momma with the older litter has babies that are 3 weeks and 2 days old

My problem is they all look like little girls to me!