Princess Ruto is Gone!?

In Ocarina of Time, Princess Ruto has vanished. I threw her at the Sapphire, but when i battled the mini boss, i died. Then when i went back and beat it, i continued on, but i can't find Ruto. I need her to get into the final boss. And I've checked every room I can get into (the only one left is the room where you get the boomerang which also needs her help)