The master sword is lost/destroyed and link has to use the chick(which looks like the great fairy fom mother and child island from WW) as a substitute weapon to recover it, based on the look alike, I'd say the chick is the great fairy and is helping link. Something also might've happened to fairy world, that link agrees to help with, in return for her helping with the master sword.

From what little information that I've heard about, that's about all I can come up with, and considering most of it is wild guessing and assumptions, that's not much.

__________________
~The statement below is True~
~The statement above is false~.