Heartbreak: The Lenka Trilogy Part 1 by John Righten

Heartbreak. 1990. Lenka Brett, a smart but unworldly young Irish teacher, volunteers to deliver medical aid when the world learns of the horrifying plight of children in Romanian orphanages. An English naval officer, Captain Simon Trevelyan, volunteers to be her co-driver. Together, they join a convoy of humanitarian aid drivers known as the Rogues, the last hope for those in areas where official charities cannot enter. Lenka falls in love with one of the drivers, but when the Rogues become the target of mercenaries, tragedy follows and she discovers her lover is not who he appeared to be.