Mariana is considered graceful by Josefina and very respectful of her elders. She has a doll like Josefina and they like to play when Josefina visits. Josefina saved her life in Happy Birthday, Josefina!, and Mariana's family was so grateful that they gave the Montoya family a melon for Josefina's Feast Day/Birthday gift, which was prized. Mariana lives with her grandparents, so it seems she doesn't have any parents. Esteban is her grandfather, and Andres Montoya's good friend and trading partner.