The Tourmaline (White Tyger Book 2) by Paul Park
Miranda ages five years in an instant, going from 15 to 20, as magic transports her from primitive America to industrial Romania. She begins to find her destiny and gather her people to her as the German elector and Nicola Ceausescu scramble to destroy her.
Even more fascinating are the parts that concern Peter and Andromeda who seem to be reincarnations of two liegemen once charged with guarding Miranda: the half-mad Chevalier Pieter DeGraz, and the shrewd and amoral Sasha Prochenko. This mismatched duo tries to rejoin Miranda by traveling through a time-tunnel five years into the future from American to Egypt, and they come out five years older as well.
They have to travel and work together even though Peter has almost disappeared into the strange persona of Pieter DeGraz and Andromeda as Prochenko is constantly shifting between dog, female, and effeminate male personas. What complicates the situation further is that DeGraz and Prochenko have always intensely disliked each other! An absorbing and interesting read.