They were an accidental litter.
Two rabbits were bought as female/female, turns out one was male. He was neutered as soon as babies were discovered. They kept mum with the three female babies... unfortunately the vet sexed one baby wrong! A male.
Resulting in two sisters and mum all giving birth a few weeks apart from each other, and in one big mess! I sexed the eldest litter and took the 3 males to prevent more accidents, and gave another local rescue's number for when the other two litters were old enough to be seperated