Mara lived out the five years. At the time of the battle, she would have been on a ship in the middle of the ocean somewhere. Which isn't to say she didn't feel the effects of it all in some way. (And since that's a part of her backstory that only a certain special few will be privy to ahead of time, I'm not going to say any more than that. )
Those five years were spent pirating, treasure hunting, learning the basic tenants of thaumaturgy, picking up a few other fighting skills, and... stuff.
Those five years were spent pirating, treasure hunting, learning the basic tenants of thaumaturgy, picking up a few other fighting skills, and... stuff.