I am trying to remember a story about a space ship watching over us for quite a few centuries. It offered its help when an alien virus was about to attack and wipe out the planet. It made its journey with a selected million of people under a lady commander for another Earth-like planet in a distant corner of space.
During this voyage the ship experimented on a girl to find the super extraordinary, the incarnated one, who was going to guide the whole entourage to this impossible goal.
A televised series has probably already been made.