Marguarita is around twenty years old in Dark Predator. She was raised on the De La Cruz Peruvian ranch by her father, a cousin to Cesaro Santos, until he was killed by a vampire. Her mother, who was a Chevez from Brazil, died when she was young.
When Etienne killed her father, he slit her throat when she refused to tell him where Zacarias rested. With Dominic watching his back, Zacarias healed her as best as he could and gave her his blood. Despite this, she was unable to speak ever again.
Marguarita is the first person to ever disobey the De La Cruz brothers, making Zacarias angry. However, he is unable to dole out punishment as he intended for her disobedience, as she turned out to be his lifemate.