Since your cats have been friendly for most of their existence together I think you will find redirecting them easier than if they had not been so friendly.
It sounds like Ramona was afraid and when she could not attack the noise maker in the street - she decided to attack the next best thing which was Bailey!
For future fights you may want to try one of these two tactics:
1. Use a Water Pistol
Generally, a water pistol set on full stream will be an attention-getter and break up a fight quickly.
2. Toss a Pillow or Large Toy Between Them
Best-scene results will be that the aggressor's attention will be diverted toward the pillow, so the victim may safely retreat.
I found these tips on Fosters & Smith:
Prevent your cat's aggressive behavior from becoming a habit by intervening early.
Keep aggressive cats separate from each other. Reintroduce them slowly when signs of aggression have disappeared.
Interrupt and startle cats that are being aggressive toward each other with a squirt of water or by shaking a bottle partially full of nickels.
Hope these things help~