I am so sorry! It‘s a stressful situation. First write in a dedicated notebook the date and times, including your call to your neighbor and sny future conversations or happenings.
Having a written record will be invaluable should you need proof or history to give to the police.
I hope it doesn‘t come to that.
Your neighbor‘s defensive reaction and accusation, without knowing anything else, makes me think she is scared too for her dog. As a hound dog owner myself I worry they will get themselves into trouble with their nose. They don‘t recognize property lines or pets. I can barely hold my male dog back, if he sees a chicken. But he doesn‘t touch my ducks bc I raised them inside with him.
Are there any other deterrents you (or you and your neighbor) can put up to block the dog from reaching your chickens?
I know our girl got lose the other dax bc the kids had the door open while they fiddled with keys. But other than the accidental release, why are her dog(s) able to get out and into your yard? If she is careless and let‘s them loose, call the non-emergency number for the police. They will have a chat with her. I would try to sit down and talk it out first. And continue to keep records in case you need them. Date, time, and description. Best wishes.