Just as a precaution, the babies will very quickly be mobile and looking for trouble. You might want to consider narrowing the openings between those lower boards or tacking on some fencing on the inside to prevent the kids from getting their heads/bodies stuck in there. Also, if you have water in a bucket for her, please take it up off the floor and hang it so she can drink but the kid can't accidentally fall in and drown.
Waiting along with you



Waiting along with you 



I do already have her water bucket hanging so the kid/kids will not be able to get in it. 
I give it at 3-4 weeks and again in about 4 weeks after that as does everyone I know. 