I think Leilani is a very pretty name. Just the thought of "heavenly flowers" makes you think this name is beautiful. I think a good nickname would be Lei or Lani.
I first discovered this name because I saw it as the name of a street on a street-sign. I thought it was a beautiful name, but I didn't think it was real. But now I know it is. It's pretty.
A somewhat famous bearer is the young Leilani Guiterrez. After being severely injured when a federal employee ran a red light on Mother's Day, she managed to stay cheerful even in times of hardship. She and her mother have appeared in commercials supporting stem cell research.
I knew a girl in elementary school that had the same name. Never came across another girl with a name like that again. It's a very beautiful name and it's unique too.