A lot of name sites seem to think that "Australian" means "we don't know so we're making this up". If any site other than Behind the Name says that a name is "Australian", it almost certainly isn't!
I've seen Lelaina here and there. It's the name of a character in a well-known film from 1994 (Reality Bites). There's also a few real women/girls named Lelaina around, though they might well have been named for the film character.
The word 'lane' in English does indeed mean road or pathway, and it is sometimes used as a name (Lane) but I doubt Lelaina has anything to do with it. Le means "the" in some languages (French for one) but Le Lane would be a very unlikely combination since they're two distinct languages.
Le- is not an uncommon prefix for made-up names, and Elaine is sometimes shortened to Laine, so perhaps it is a coinage based on Elaine. Or it could be a creation based on Leilani. I can't find anything definite online.