You want a box that is a little bit bigger than the doe herself, about two inches longer and wider. Just big enough for her to get in and turn around in.
I have used a shoe box in the past and that has worked well. Or something from wood would work too.
Put some bunny safe shavings or other soft litter in the bottom (about 1-2 inches) and then fill the rest with hay. Mom should start rearranging the hay closer to her due date or possibly as she starts to get labour pains (some buns procrastinate). If she doesn't build a nest, you can make a fist sized hole in the middle of the hay and put the babies with any fur that mom pulled in after they are born.
If she starts to build a nest somewhere else, move the box there and put her nest in it. Keep doing that till she gets the idea or has them and you move them into the box.
Check at least twice a day from now on because you don't know the exact due date. Make sure there are no hidden areas she can go in to have babies that you wouldn't be able to access the babies in.
For now, make sure she has lots of hay or straw to build a nest if she so desires. And just be prepared to move the babies into a nest if she doesn't figure that out on her own.
If she has not fed them after 24 hours, you can put her on the nest while giving her a treat. This will allow the babies to suckle from below her (rabbits nurse by standing over the babies), and this will also stimulate her to produce milk. Do that twice a day for at least 5 minutes, and she should start getting the hang of it as her milk production increases from the increase stimulation.
You need to sort through the babies as soon as you see any. Take out any that are dead, warm up any that are cold and check to see if they have been fed. If you post pictures of the babies, we should be able to tell you if they have been fed or not.
Good luck!
-Dawn
