When my youngest was younger, she wanted to be called Sally. All her dolls and even a cat or two were christened "Sally". I took her with me to the grocery counter to order her Birthday cake and when the nice lady behind the counter asked what name we wanted on the cake, I looked at my youngest expecting her to give her name and instead, out comes "Sally". So Sally it was.
When I was about the same age, I wanted to be called Cindy. Too many episodes of the Brady Bunch. No one in my family would oblige. This is, no doubt, why I am all mucked up as an adult, yes?
My oldest used to carry around an imaginary friend named Robin in the palm of her hand; and at times wanted to be called Robin herself.
I can't recall my middlest wanting to be called by someone else's name, but she did ask to be called by her middle name when she was about ten years old. It stuck. Sort of. I actually use both of her names interchangeably and often, both, in the same breath. Making me sound like I have four daughters instead of three, or much like a crazy person.