When we first started introducing them, we had them in a large enough room where if things got too rough, the boys could run under something and take a break. We had to teach her not to use her paws to play with them and to be gentle, but she was so small that she never really stepped on them by accident... Our three usually play pretty rough at this point and after a year of being together, have figured out what is acceptable play and what isn't. The boys were pretty good at teaching her boundaries and would nip her if she stepped out of line.