The FND female lieutenant Peña was one of the three lieutenants loyal to José Castillo who caused the death of Carlos Montero, during her leisure day she went to the "Terme di San Gómez" "Costa del Mar". Pistoleras such as her and Ría Campos actually wield pistols as the name implies, not Skorpion.
Similar to Pistoleros in the previous game, her combat style is the same as FND Military Clerks, FND Pistoleros and FND Officers, although much weaker due to her being an actual pistoleras, hence the slower rate of fire compared to FND Pistolero's Skorpion and lacking special abilities that FND Officers have.
She is killed by Dani Rojas in the mission led by Camila Montero "Death sentence".
One of the notes that can be found in that area is this.
"SPECIAL DISCOUNT FOR SOLDIERS
Guardaro
- 10 Toccaro
- 25 Full service
- 50 Talk to Inóz."