Yes my gerbils are female. Females do tend to de-clan more then males but my girls are happy little gerbs. Yes they are from the same litter. It is called a bin cage although not usually suitable for gerbils I found a bin that has no edges for them to chew so they can't chew their way out. My cats got in my room and attacked my gerbils they were both fine (although Pixie is missing part of her tail) the cats broke the tank lid and it would have cost me $50.00 to repair or to get a new one. The bin cage was the best option. I have not had gerbils before but I have researched them greatly. Sorry about your gerbils.
Thanks =D