Pronounced Kay-lee? I've seen it a bunch, spelled Caley, Kayleigh, Kayley, etc. I had a friend growing up named Kalee and she pronounced it that way too.
It is a real name. Some places it has a meaning some it doesn't. It used to be one of my favorite names:) I think it's kind of a spin off of Kay, or something like that. Kind of a made up American name.
Re: is this a real name?
It sounds contrived (not sure if that is bad or good though). Sort of like "Maura" (instead of Laura).
Guess someone decided to modify Hailey/Haley.