In Love and War: The Lives of General Sir Harry & Lady Smith

 
From the publishers:
The manner of their meeting was unprecedented. During the lawless mayhem that followed the capture of Badajoz by Wellington, a fourteen year old Spanish girl sought the protection of Captain Harry Smith. They fell in love and married shortly after. From then on their lives and careers were inextricably linked and Juana not only followed her able, brave and ambitious husband but built her own formidable reputation.
 
The book describes their lives together starting with the remaining battles of the Peninsula War. Harry Smith was already a favourite of Wellington, who insisted most unusually on giving away Juana in marriage. His card was marked and his career prospered. He distinguished himself in numerous campaigns and theatres. Most particularly he was credited with the victory at Aliwali in India.