It's a diminutive of my last name. Like Pete for Petersen. My given name is Sophia, which I absolutely hate,
and avoid using as much as possible. Lindy is also my Dad's nickname, (which leads to occasional confusion when I visit home) and I laid claim to Lindy early to keep one of my brothers from using it. It's been my nickname since I was a child. It's also pretty much gender neutral. I like it.
Lindy