Dude that SUCKS!
We have a lady like that & she is the "condo association president"...in other words she is in charge of driving everyone crazy!
She's like 100 years old and just a mean, grumpy, old lady...when we first moved in she used to start with us all the time because we were like the youngest in the condo complex...she used to write us letters all the time & I would come home from work & she would tape them to our door...Finally I wrote her back this 5 page letter & taped it on her door, and pretty much told her to go F-herself (not in those exact words of course, I dont want to give the lady a heart attack...or do I? But you know what, after my letter, she has not once bothered us since...that was like over a year ago...no letters from her to date !
Honestly, sometimes you just have to stick up for yourself. Your neighbor thinks she can run all over you, probably because you have not confronted her seriously yet, but if you do, most likely, she will back off.