Your female is probably 12-28" that won't be enough Space why would you only give that much. Divide the tank in half the pups need space to move around as well and most probably die if she has a large litter. I would most definitely give her half the tank at least. A foot of moving space she might get stressed and abort the babies prematurelyi actually have a question on this... so if you divide out a pregnant female. does she normally just sit there? its ok for there to be practically no swimming space? for example i have mine in my 300. if she gets pregnant i seperate her off from the others... 8 foot tank... so i prob would seperate 2-3 feet. this is enough space?