Rosi's Time — Edward Eaton

Rosi Carol has managed to settle into her Uncle Richard's New England castle, despite having her family's so-called gift thrust upon her. Rosi has the ability to step through time, which means she also bears the responsibility to be time's Guardian. Or rather Apprentice Guardian, as her Uncle Richard keeps pointing out. When she and her friends are dragged through a time portal into the past, Rosi must determine not only where they are but when they are and how to restore the timeline. [Book 2 of the Rosi's Doors young adult fantasy series released in 2012 by Dragonfly Publishing, Inc.]