I too brought home 2 littermates, Bella and Dixie when they were 9 wks old. Yes at first I kept them together in the same crate for sleeping, same car seat for riding in the car,and eating from the same bowl. Even when they went to the groomers I had them stay together. Most of the time they were fine with it, sometimes they would fight but nothing really crazy. Bella liked to lay around as Dixie always wanted to play. Eventually I did separte them as I was afraid for them to get to attached to each other. You have to play it by ear and see how it goes. My girls are now 4 yrs old and they still bicker at times and then will lick each other and cuddle. If you have any other questions let me know. I will try to help as best as I can. Good Luck
Kathleen-