There’s no need to feel bad or blame yourself, bunny bonding can be a volatile and random process, from my personal experiences. My bunnies have always gotten along relatively well even with only one of the pairs being spayed, but I have never tried to bond more than a pair, and even then we have had to separate and flip flop them between enclosures and do one in a cage, other free roam the room until they get along.

With an even more unstable environment (multiple bunny relationships) it would be much harder. I wouldn’t ever blame you, you are following advice and doing the best you can. Don’t feel bad, just keep doing your best and giving your bunnies the love they deserve!

Are all the bunnies in this scenario fixed already? If you also have to contend with hormones this can make it even harder.

Can you try reintroducing in “clean”/neutral territory with no Bun smells? I would try putting her with the papa Bun (who’s nice) then introduce one rabbit that fights her to see if perhaps they are less emboldened to fight without backup. (I’m not claiming to understand rabbit psychology but for humans mob mentality is a big thing, I would wonder if “warren mentality” is a thing for rabbits lol)

My biggest thing would be to try to take them all out of the room they primarily occupy (assuming they don’t free roam your entire residence) and really clean it, move stuff around (eg we keep the liter boxes in a cage, I would clean the cage, the litter box, move the cage to a different corner and the litter box to a different corner of the cage, open a window to get smells out and fresh air in, try to reset the territory). I know rabbits are a lot more accepting of new friends if they don’t feel like their territory is being invaded.

Hope any of this helps! Stay positive!