I was kinda on the opposite end of the stick once.
I was on national park trail walking one way, and another guy was walking the other way.
I realized that he looked like a certain sociopathic guy I work with years earlier who ripped me off of money and caused other problems.Then I thought "NAW...he is too tall to be that guy, but..."
I paused, turned, and eyeballed him, and eye balled him, and eyeballed him, - especially his facial features. Gradually I decided that they were not the same person-though the resemblence was strong.
But this innocent guy on the trail got REALLY spooked at me -but kept walking his way-being purposely nonchalant- but I could tell he was unnerved by me ( my glaring at him might well have seemed 'demonic').
Now..it was only a few seconds, and I didnt turn around follow him and stalk him, nor anything like that, but.
But this thing you experienced might have been some kind of mistaken idenity- and she mightve been staring at you precisely to see if your features matched some person she knew from before who looked like you-who mightve victimized her in some way.
Maybe.