to never ever punish the dog for her fear/aggression towards strangers.
No yelling, startling, leash yanking, hitting, etc..
the benevolent leader, your are responsible for your dog. If anyone
tries to touch your dog when she is upset, step in front, block that
person from touching your dog. If the person doesn’t want to listen,
then either remove your dog (no snatching or yanking) or politely ask
the visitor to leave.