Themes such as perseverance and courage could be in the story. The girl needs to persevere through the long periods of separation. She has to be courageous in facing the possibility of losing the soldier in combat. And there might also be a theme of patriotism, as the soldier is serving his country and the girl may support him in that noble cause.
A 'a soldier's girl true story' might start with how the girl and the soldier met. It could be a chance encounter or they might have known each other from before he joined the military. As the story progresses, we could see how she copes with his absence when he's away on duty. She might write him letters, keep his memory alive in their hometown, and struggle with the daily worry about his safety. The story could also touch on how their relationship changes over time due to the military lifestyle.
Typically, the main characters are the soldier and his girl. The soldier is the one who is committed to military service, facing the rigors of military life. His girl is the person who is in a relationship with him, and she is likely to be the one waiting for him, dealing with the emotional ups and downs of his absence.
The 'Soldier's Girl' true story might be about the unique bond between a female and a male soldier. The girl could be facing difficulties like the uncertainty of the soldier's return, and also the social and family pressures that come with being in a relationship with someone in the military. There may be instances of how they met, how their relationship developed over time, and how they coped with the military - related constraints.