
I have been sleeping next to mine and will do so until at least 3 weeks old. By that time with my last litter, mum did not want to be in with them all night. I used to make her go in at about midnight and then hubby would get up at 5 and let her back in again. If they woke up during the night, I would take her with me and give them a top up but she REALLY, REALLY didn't want to be in with them all night. It may be different with this girl and in that case I will do what she feels comfortable with.
Do keep me posted on how you get on with the box over the next few weeks as I haven't whelped in mine and don't think it would last more than the 3 weeks I managed with it for my last litter. However, my breed pups may be totally different in behaviour to your's and less rough with it.
I wouldn't normally advocate bathing mum so soon but she was having difficulty toileting being so caked in blood and amniotic fluid. We tried using a well dampened towel but it didn't work and the pups were getting covered in it. The little chap who likes to sleep between her rump and tail was literally drenched all day yesterday so we felt it better to wash her.
I think you will find that both mum and the pups will settle within 24hrs and there will be less screaming and whining and once she's sure they're ok, not going anywhere, definitely her's etc she will stop obsessing over their bums all the time and start to rest - only cleaning bums when required :)
My pups are already very mobile, dragging themselves from one end of the box to the other, have filled out and are already bigger than my hand. They seem to have doubled in size over 24hrs..Little fatty bum bums :)
ETA: I think I may have 2 with bumps where the umbilicus was so far...