My gran died when I was seven years old. A few days later I woke up in the night and got out of bed. My gran was in the room, she held out her hand and said "Hello dear". I got back in the bed and hid under the covers. When I looked out again she was gone. True Story.
Further to Mick O'Toon's post did your granny have white hair, wear tracksuits and loads of tacky jewellery?