Is it ok to breed sibling rabbits?

[Usama]

my doe was pregnant for the first time without me knowing , and found she had delivered her kits , 3 dead and two alive, they were cold so i warmed them with a hot water bottle , but they didn't have nest made by mum so i placed a towel in the cage and put them there. The smallest of the two was scattered the following day so i placed him with the other kit , but when i came home he had one arm completely ripped off could the mother have done this? he was still alive so i don't think it was cannibalism. The other kit seemed to be fine because she was licking him and lying on him to keep him warm but he didn't survive that night either. The point is that this time I am prepared and she has been with a buck for 24 hrs and now she is by herself so where do i start? Is it OK for brother and sister to breed? thank you

[PetsCharm]

It's not desirable that brothers and sisters are bred as it can result in genetic problems. Also, any unaltered (i.e. not spayed or neutered) rabbits should have their own cages and not be housed together. Rabbits are territorial by nature and should not be housed together.