The Messenger's Handbook — Pamela DuMond

Infinity. Life. Death. Rebirth. Some souls are meant to be together, but the course of true love can be dangerous and often deadly. When sixteen-year-old Madeline falls in love with Samuel, a boy who lives hundreds of years before she is even born, she risks her very existence to be with him.
 
Madeline's from present day Chicago when she is pushed onto the train tracks, and accidentally time travels to a bloody war between the Natives and the colonists. She falls in love with a Native boy, Samuel. But, she's living in the body of a colonial girl and their love is a crime which carries harsh punishments.
 
Madeline discovers that she is meant to be a Messenger, a traveler who if properly trained, can slip through time's fabric at will. The Medicine Woman mentors her. But Madeline doesn't fit in this world. She's different from the other colonists. Rumors of witchcraft and spying arise. Deadly Hunters, dark-souled predators as well as skilled time travelers, crave Madeline's powers. Can Madeline find the way back to her future? And will that future include her one true love, Samuel?