|“||Leo, listen to me. Fire is a tool, like anything else, but it's more dangerous than most. You don't know your limits.||”|
Esperanza Valdez received a college degree in mechanical engineering, but never received a job in that field because she was never taken seriously as a mechanic because she was a woman, resulting in Esperanza starting up a machine shop. Sometime in 1995, Esperanza had a relationship with Hephaestus, god of blacksmiths and fire, resulting in the birth of Leo Valdez.
From 1997 to 2000, the Queen of the Gods, Hera (in the form of Tía Callida) came to her house and babysat her young son to prepare him for his life as a demigod. Esperanza was enraged by this, insisting that Leo was far too young, that he was still her baby.
It was stated by Leo that while Esperanza did not have a lot in life and lived in poor conditions, she was always happy, because she had Leo.
Three years after the departure of Hera, Esperanza Valdez was killed in a fire at the machine shop caused by Gaea, when the Mother Earth faced eight-year-old Leo Valdez. Her death resulted in Leo running away, and his eventual enrollment in Wilderness School. Leo believed he had caused her death for a long time.
- Esperanza always called Leo "mijo" (me-ho), which is an endearment term used for males in the Spanish language. It is often used by parents to address his or her son; as well as other close family relations. It is a contraction of "mi hijo", meaning "my son".
- In Spanish, Esperanza means "Hope."
- She is similar to Sally Jackson, Percy Jackson's mother and a lover of Poseidon in the aspect of only wanting their son's father around to be with their respective children, not for themselves.
- Her favorite band is The Rolling Stones.
- She may have the ability to see through the Mist, as she knew Tía Callida was Hera.