#in that case is any skyloft girl eligible for hylia's memories?

[ladyrijus]

Okay, admittedly it has been a while since I played the game, but did Skyward Sword ever elaborate on how Ghirahim knew Zelda was Hylia's mortal form?

I get that the likely answer is his mystical demon lord/sword spirit abilities.

Another possibility (mostly headcanon than actual canon) could be that he originally was supposed to act as a counterpart to Fi, a dual blade meant to be used by Hylia, so he can sense the goddess's presence.

... But it would be infinitely funnier if he knocked Zelda off her loftwing specifically because he saw her participate in the Wing Ceremony as the actress for Hylia and went "YEAH THAT'S HER." without any actual tangible cues for her divinity.

That would mean, in any other universe where the girl who played Hylia was different, he would have been wrong.

Just imagine. It could have been Orielle. She specifically made it known that she wanted to participate in the ceremony as Hylia. Or Karane, she was in the Knight Academy and could have done it for sake of tradition. Or Peatrice. Because... it's Peatrice, come on.