Ruby Red, The Ruby Red Trilogy 1

Gwyneth Shepherd's sophisticated, beautiful cousin Charlotte has been prepared her entire life for traveling through time. But unexpectedly, it is Gwyneth who in the middle of class takes a sudden spin to a different era! Gwyneth must now unearth the mystery of why her mother would lie about her birth date to ward off suspicion about her ability, brush up on her history, and work with Gideon--the time traveler from a similarly gifted family that passes the gene through its male line, and whose presence becomes, in time, less insufferable and more essential. Together, Gwyneth and Gideon journey through time to discover who, in the 18th century and in contemporary London, they can trust.
Kerstin Gier's Ruby Red is young adult novel full of fantasy and romance.