* A misspelling: It might be a misspelling of a different name, like "Kelli" or "Kelly."
* A unique name: Some people create unique names for their children, so it could be a newly invented name.
* A name from a specific culture or language: It's possible that "Kellina" is a name with a specific cultural or linguistic origin that is not widely known.
If you can provide more context, like where you encountered the name, I might be able to provide a more specific answer.