OMG she threw an egg at me!!!

[seismic wonder2]

Call the police, report it as a drive-by egging.
Tell them she knows you are allergic to eggs and it was an attempted murder.

Assault with a deadly ovum with eggstinuating circumstances.

 

[The Chicken Lady]

The next time you see her, just walk away and don't say anything. Sometimes it pays to be the bigger person.

Her goal is to make you react, and if you do ANYTHING, you'll make her happy. It will bug her more if you pretend like she doesn't exist. (Don't make an obvious act out of ignoring her, either).

It's like dealing with an internet troll in real life. Don't engage, and just move on.