Before she got lumbered with having to share with me, my sister, who is 5 years older, used to be quite cruel.
She knew I was scared of the dark, and would creep up the stairs, making just enough noise so that I'd know someon (or something.....) was coming.
I'd lie terrified in bed calling out "Mum, Dad, Anne, is that you??" She would say nothing....
Once, she even hid under my bed before I went to bed, then lay there and started making scratching noises once the light was off.
We do get on now, though. I see her maybe three or four times a year 