Handling Newborn Kittens

Our 1 yr old cat, Nala, had her first litter on Tuesday night. She birthed 2 kittens that night. Then last night (more than 48 hours later!), she had 2 more kittens. Unfortunately, one was still born, but the other seems healthy. That's not my question though, because since discovering this forum, I see that is not all that uncommon.

My question now is, how soon can I handle the kittens? Nala had her kittens in the lining of our couch....not the nice, warm box I had originally prepared for her. I was planning on letting the little family hang out in the couch for a couple of days, then move them to the box tonight. But now that there is a brand new kitten in the mix ...is it ok to go ahead and move them now?  We've pretty much left them alone, not touched them at all since they've been born. I guess I'm just worried about moving them to the box, and then Nala moving them back under the couch.

Advice?

Yes, you can move them to the box.  Make sure Nala can see where you are putting them and she should follow.  There is a chance she will try to move them back.