User blog comment:Zaffie/Some Random Fails/@comment-1314424-20101114195909/@comment-1839575-20101114222801

Except that I'm pretty sure it's biologically impossible for cats to get pregnant while they are nursing... but yeah, that would work. Sadly, they never said anything about that. And I know, there was always huge huge huge 'oops, I forgot you were my sister...' in all the original ones. It gets better later on when they start catching up with their continuity and realising who gave birth to who, in ThunderClan at least.