UFO sighting - the only one who remebers is the one who didn't see it - circular bright hovering craft just above the house

It was just after dusk; I was 9 years old sitting in my grandmother’s kitchen floor playing with jacks.  My grandmother was also in the kitchen, standing at the sink washing dishes, and her daughter (my aunt) was just off the side using the phone and looking out the sliding glass back door.
Suddenly my aunt let out a terrifying scream and was pointing upward at something just outside that door.  My grandmother leaned over and was looking out the window in front of her and terror struck her face as she ran to that door.  They were both just standing there, with their mouths and eyes wide open.
Frantically I was asking, "What’s wrong?  What’s going on?," but I couldn’t see "up" from behind them.   I knew something was terrible from the frightened looks of their faces.  Finally my aunt mumbled, "It’s a UFO," and I wanted to see too, but I was too scared to look then.  They began talking about the bright white lights surrounding this "UFO," and how close it was.  And just as quickly as it came, it was gone.   By the time I got to the door there was nothing to be seen.
Many questions later revealed that they believed it was a UFO because of its circular shape and the lights all around the exterior.  It was unlike anything that was normally flying in the sky.  They said it came real close to the earth; that it was just above the roof of the house and hovered in that one spot for maybe 10 seconds and then shot off like a bullet into the unknown.
While reminiscing years later, I brought up that night during a family gathering.  My grandmother and aunt both had no recollection of the event whatsoever.  It hadn’t been that long ago and they both had excellent memory.   I had thought maybe they were joking with me, but they really didn’t know what I was talking about and declared innocence when I asked them if they were just playing a joke on me when I was a kid.
I still ask them occasionally if they remember and always get an unsuccessful response.
My memory of that night is quite vivid; I could never forget the sound of her screaming, and the looks of shock in their eyes.
Source of report indicates that the date of the sighting is approximate.  PD