Estelle Jackson and her husband, Jim Jackson, both died on a plane flight when it crashed down in a field 150 miles south of Lake Ontario at 3 A.M, leaving their young daughter, Sally, an orphan. Neither of them survived the crash and the cause of the crash was left unknown.
After their deaths, Sally taken in by Jim's brother, Rich Jackson.
Percy briefly mentions Estelle and Jim when talking about his mother backstory.
Percy mentions Estelle when stating that his half-sister is named after their shared grandmother.
According to her obituary, Estelle was a kind woman who often helped out their neighbors.
- Estelle is a female name originating from the southern region of France and surrounding countries known as Occitania. It means ''star''.
- Jackson is a very common name of English and Scottish origin, coming from "Son of Jack" as many U.S political parties.
- In The Ultimate Guide, her name was said to be "Laura".
- In The Ship of the Dead, it was revealed that Estelle's granddaughter, Estelle Blofis, was named after her.
- Percy Jackson: The Ultimate Guide, Page 13