River of Time Trilogy by Lisa Tawn Bergren

Lisa Tawn Bergren's new YA series, River of Time, is romantic, historical fiction in which the plucky heroine doesn't have to fear a vampire's bite but must still fight for her life.

In Waterfall, American teenager Gabi Betarrini accidently finds herself in Fourteenth-Century Italy . . . Knights. Swords. Horses. Armor. And Italian hotties. Most American teens want an Italian vacation, but the Betarrini sisters have spent every summer of their lives there with their archaeologist parents. Stuck on yet another hot, dusty dig, they are bored out of their minds... until they place their hands atop handprints in an ancient tomb and find themselves catapulted into the Fourteenth Century and in the middle of a fierce battle between knights bent on killing one another.

Mom touched my underdress—a gown made six hundred years before—and her eyes widened as she rubbed the raw silk between thumb and forefinger. She turned and touched Lia’s gown. “Where did you get these clothes?”              

Gabi knows she’s left her heart in the fourteenth century and she persuades Lia to help her to return, even though they know doing so will risk their very lives. When they arrive, weeks have passed and all of Siena longs to celebrate the heroines who turned the tide in the battle against Florence—while the Florentines will go to great lengths to see them dead. But Marcello patiently awaits, and Gabi must decide if she’s willing to leave her family behind for good in order to give her heart to him forever. 

When Gabi and Lia finally learn to surf the river of time, they realize they must make hard choices about life and love in the third and final book in the River of Time series.   Gabi and Lia Betarrini have learned to control their time travel, and they return from medieval Italy to save their father from his tragic death in modern times.   But love calls across the centuries, and the girls are determined to return forever—even though they know the Black Plague is advancing across Europe, claiming the lives of one-third of the population. In the suspenseful conclusion of the River of Time series, every decision is about life … and death.