Captain Maria Carnela features in the OVA episode "Clinical Chart 3: Decoration of Maria and Her Comrades." A captain within the Ortega Republic's military during its conflict with the Federal Unites Air Force, she recruits surgeon Black Jack to operate on an undisclosed patient. This patient is later revealed to be her father, General Cruz, the republic's leader accused of international crimes by the Federal Unites, who suffers from terminal cancer.

As General Cruz's daughter, Maria's actions are defined by profound familial loyalty. She commands the unit assigned to escort him safely back to Ortega territory after Federal Unites forces free him during transit. Maria sustains a gunshot wound to her eye during this mission yet persists in prioritizing Cruz's safety and urgent medical care. She coordinates with Black Jack to perform an emergency thyroidectomy on Cruz under hazardous moonlight conditions amidst active combat, striving to extend his life despite the advanced cancer.

When Federal Unites elite forces launch a decisive attack, Maria orchestrates a diversion with her remaining troops to ensure her father's escape. This act of sacrifice leads to her death in the ensuing engagement. Her actions enable Black Jack and Cruz to reach the border, though Cruz is subsequently executed on President Kelly's orders. Maria's military dog tags are later discovered among Black Jack's possessions, serving as a physical reminder of her role.

Her character design includes violet hair and blue eyes.