Doe had 3 kits 2 DOA. What now?

[LionheadBuns]

I'm new to breeding lionhead rabbits. my 8mth old doe bred with a buck quite a bit smaller than her. Two kits came out DOA, looking stretched out and long. I found a third under some bedding and created a nest for it. Its much smaller than the other two where. But is active. She seems uninterested in him though. No fur pulling and his tummy looks empty. She just had them yesterday. Her sister was in the room we keep them in. I woke up early this morning to them fighting. I tried breeding around the same time, so if either had issues I could foster kits with the other.

I immediately separated them, no blood. Just a bit of fur. I have a few cages available. One I put the remaining kit in with straw and fur from a previous does litter. Should I keep her in the cage with it? Or keep the nesting box out of harms way and leave it with her 2x a day for feeding.

Theyre indoors and its in the 70's. I'm worried about her trampling him.
The other doe could be due any day, so I'm assuming I should cage her as well? Shes a first time mother also. Hasn't shown interest in hair pulling, or nesting. But shreds pads and digs. I'm hoping if I cage her, the kits will have a better chance.

I have a doe with a litter of 5. Almost 4 weeks and doing very well. Is it too soon to let them have a play pen space with mom?

Thanks for any advice!