I am a girl and my name is Jonnie, which is usually known as a boy's name spelled Johnnie. I like it because I don't know any other girl with the name, and because I don't know anyone who spells it that way.

Jonnie/Johnnie was used for girls mostly in the late 1800s/early 1900s. It was probably thought of as a feminine form of John, though it fit the trend of giving girls masculine nicknames (others that were popular for girls: Bertie, Jimmie, Mattie, Willie, Billie, Ollie etc.)
See Also: John

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