Jade is only sixteen, though sometimes she feels much older.
Sometimes she feels old when she when she is with Cat, making sure that she doesn't get herself into too much trouble.
Sometimes she feels old when she realizes that the world her friends live in is corrupt, dark, and dangerous.
Sometimes she feels absolutely ancient when she is lying next to Beck, doing absolutely nothing but listening to his steady breathing, and she feels as though she has known him for an eternity.