Pasteurella multocida. If you rabbit has this, it's very contagious so be sure this rabbit is staying far, far away from your other rabbits. Also, be sure your not sharing food, toys, etc. with your other rabbits.
What other symptoms does your rabbit have? Runny nose? Sneezing? Watering eyes?
You should never breed this rabbit, she will never recover from this illness, she will always have it, but you can control the symptoms.
The fact that she came down with this is a sign that she has a weaker immune system, which she could possible pass down to offspring.
It can be a very long, difficult process to find the right antibiotics, not from personal experience, but from hearing from people who have tried antibiotics. When a few of my rabbits starting showing symptoms, I culled them. It was a very difficult decision, but I firmly believe it was the right one.
Wishing you and your bunnies the best of luck with this annoying bacteria.