Annie, Between the States by L. M. Elliott

Annie Sinclair's Virginia home is in the battle path of the Civil War. Her brothers, Laurence and Jamie, fight to defend the South, while Annie and her mother tend to wounded soldiers. When she develops a romantic connection with a Union Army lieutenant, Annie's view of the war broadens. Then an accusation calls her loyalty into question. A nation and a heart divided force Annie to choose her own course.