2bunnies in same hutch one pregnant?

I have two girls and one boy rabbit . The girls share the same hutch and one of them just had a baby but it died . The other girl didn't seem to bothered about it ( even though it separated when she was giving birth ) but when I visited the vets he said it would be ok for the rabbits to mix . My other girl rabbit is pregnant now and because my hutch has a higher a lower type of hutch ( but cannot be separated) I think the other one will sleep on the top half ( above the bed ) and the one which is giving birth in the nest / bed.