Are the younger buns neutered yet? If not they cannot live together even if they are in fact the same sex because they will fight. If you put one of the unnutered young buns in with the spayed mum chances are they will attack the mum I am afraid. Buns do hump to establish dominance but in unneutered pairs it quickly leads to fighting

Unless they are very young bunnies, unneutered and unspayed rabbits should not be kept together, even if they are the same gender. When rabbits reach around 12 weeks of age, they may or will soon begin entering puberty. With all the hormones that brings, they can become territorial and aggressive. That can lead to fighting and severe injuries. You need to get Snow and Tiger neutered, then after a month or so you can rebond them. If there is a possibility that Snow is a female and you just recently saw the humping, she could have an emergency spay in case she is pregnant. The main thing now is to keep any unneutered or unspayed rabbits apart from any other rabbits. Even if one of the rabbits has been desexed, there will still be problems if one is still intact.

That’s a good plan. Being from the same litter or being a parent with an offspring doesn’t prevent aggression or fighting. You can keep Snow and Tiger in the same room, but not in the same cage and they can’t be out exercising together either, until after their surgeries and recuperation.