Thanks again for your great input guys!
My second female has had her litter and so far, no signs of aggression from her. She still seeks out attention, etc.
The more I think about it, the more I agree with you guys. At this point, I am planning on culling this whole litter and mother when they are weaned. I am going to handle them minimally (only cleaning) and unless some of them appear to be extremely mellow and outgoing, all will be culled. If I do keep any, I will only hold one back just to do a test breeding and see if she also shows aggression. The other female's litter is pretty big (11) so that may give me enough females / males to hold back.
Thanks again for your advice, it has been a great help!