Novalee Nation was the main character in the novel Where the Heart Is. It has been a while since I've read it but I remember the characters talking about the importance of names at one point. I really don't remember but perhaps the book mentions that Novalee means "chasing butterflies"? If what was written about the meaning was incorrect I could still see people believeing it, resulting in those "name" websites and their possibly false information.
Anyway, I am completely unsure about this being in the book or not :P If you are really interested I'd suggest looking at the book. Otherwise I'd probably just agree with SugarPlumFairy that it is from Novalie/Nova.
http://www.behindthename.com/pnl/70608 *interesting-meaning names