@bookangel555 None of them was chosen because of the others. That's important. Camilla wasn't created as another protector for Nina, Eddie wasn't selected because Camilla would eventually appear, and Nina's birth wasn't engineered to bring the three together. Their individual destinies existed independently. It's the magnitude of what is coming that causes those destinies to intersect.
You could almost think of it as fate recognising that what is coming is too big for any one prophecy to solve.
So circumstances begin aligning. The descendant of Amneris is there. The person Osiris judged worthy to stand beside her is there. And somehow, amongst all the schools and all the places in the world she could have ended up, the girl Isis has chosen (a future great mage carrying a bloodline stretching back more than three thousand years) is standing in the same place, at the same time, preparing to fight the same battle.