I'm sorry it ended this way. It sounds like your neighbor is a little off her rocker. I hope she leaves asap so you and your son can get on with your lives without her unwarranted interference.
All this makes me grateful for my neighbors. I live in a semi-rural area. My closest neighbors love chickens and even roosters! They were disappointed when I told them I wasn't planning on having any roos (well, I have 2 now). My other neighbors are - ahem - "growers," for personal use, I'm...
Could you maybe talk to her? She sounds unreasonable, but I find these things are often the result of misunderstandings. Maybe offer her free eggs (and, no, I am not condoning egging her house). Your neighbors who have chickens might be able to offer advice, too.
Might be worth a try? Worst...