Hey Marc, first thing is to cut the nails, I use a baby nail clipper they scratch mama if you dont and she does not like it..LOL, I use a little pen that I got at petsmart for the first few weeks after they start climbing out of the box, is easy for mama to get out but it keeps them in. i also put the pee pad right at the door and as they get older I start moving it along. enclosed are a few pictures of my litter of yorkie jacks with my setup..and when the little pen does not hold them anymore they graduate to the big pen until they go home or join the rest of the pack at home..
hope this helps you a bit..
Carmen in nj