Captain! Is this battlefield here?

Elite Special Forces Captain Lee Yoon-ah was a soldier to the bone with no time or sense for romance in her life. However, after being hit by a shell while dispatched overseas and dying, a completely different world unfolds in front of her. She wakes up in the body of Rosalie, a tragic mob character in her friend's romance fantasy novel! After taking a deep breath and shaking her head for a moment, she decides to tackle this new situation like it were just another battlefield and to change Rosalie's life as the young duchess abused by her step-mother.
"This is a class society." "I've had enough experience with a hierarchical society – the military – I'm tired of it."
"Are you disobeying my orders now?"
The former soldier becomes the young lady who conquers the dukedom with absolute charisma! However, in the process, she unintentionally finds romance…
"Duke, how does it feel to kneel down to the Crown Prince? It's the first time you've kneeled down to anyone other than the Emperor."
The original male lead, not the female lead, falls to his knees. Can a soldier, who didn't care about love, win on this battlefield?