After our last foster kitties left, we cleaned the big room thoroughly and then moved Mouse and her kittens into the “Jiro Palace” in the corner. It’s the big cage we built for Jiro, our own feral rescue, and it’s a great place for kittens. If there’s a way to find danger, kittens will find it – but we feel that it’s a pretty safe spot.
Mouse disagreed. We moved everyone on Sunday, and she has been frantic ever since, especially at night. She climbed the walls – literally. She climbed the wire front all the way to the ceiling. I spent six hours in the cage with them the first night, to help her calm down. At 5′ on a side, it wasn’t totally uncomfortable, but I think I dozed off a total of 5 minutes.
The next day I decided the best solution might be to allow her to come out. We opened the door and put a couple of boxes to help her get over the lowest panel, and out she came. That solution worked for a few hours, and she explored the room and jumped back in regularly to feed and look after the babies. Then she decided to move them all out too! I should have seen that coming. Luckily I heard some squeaking, went in to see what was going on, and put back the two kittens she had carried out. I shut her back in, and then spent a couple of hours that night staying with her again, being the voice of calm.
In their new digs, Mouse’s family quite like the Jiro Palace. Mouse herself, not so much. 
Mouse is definitely a little tense, but the kittens are fine as long as the milk bar is open.
The next day we tried it again. She is a smart kitty. She pretty soon figured out that she could come out only if she left the kittens in the safer confines of the cage. She seems to have accepted that, and the arrangement works pretty well.
The kittens made the transition quite well. Overawed a bit at first, they quickly found their favorite spot and piled up the way they do.