Hero Or Villian? Even I don't know... (Percy Jackson)

"And when Olimpus is on fire, still frozen in ice, The Daughter will raise up. The Child Of Olimpus, daughter of all twelve godsess. Hair is fire, skin is ice, and her eyes are forest. She will be Olimpus' dream, or its worst nightmare..."
That's what the prophercy says. And I, Percy Jackson, have to find The Daughter. But how the hell do you find someone whose name, adress or even age you don't know? And if you find her, how do you tell her that she's Child Of Olimpus, without being sent to madhouse?
Don't ask me, because if I knew answers, I wouldn't be in all this mess...