What's in a name?

During the creation of The Fortune Teller's Gift I changed my main character's name about three times. While I had no trouble coming up with a first name for her, it was harder to come up with a last name. I thought about giving her the last name King. I thought the first name and last name went together well. Her first name is Mackenzie, but everyone in the novel (other than her father) just calls her Kenzie. I was editing the novel and decided to post about it in one of my writing groups, where someone informed me that there was someone who the same name, so I decided to change it. I googled most popular last names in Louisiana and came up with another last name that didn't really go with the first name, and then I just changed it again.