Shards of Honor by Lois McMaster BujoldRead about the other books on the list.
Bujold’s take on martial culture can come off as overly romantic, even rose-tinted—but at the end of the day, her handling of conflict is grounded and uncompromising. In the early Vorkosigan books, she brings a level of attention to her characters as individuals that sets her work apart from the bulk of military SF. Her willingness to confront mental health as an important aspect of a soldier’s life is encouraging, because the psychological consequences of violence are so often slept on by writers who take the Hollywood approach to war.
Cordelia's Honor (an omnibus of Shards of Honor and Barrayar) is among Joel Cunningham's seven best sci-fi books featuring strong women and Thea James's eight best women in military science fiction.