Estelle Jackson

Laura Jackson is the mother of Sally Jackson, the wife of Jim Jackson and the mortal grandmother of Percy Jackson.

History
Laura 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 is left unknown.

Her daughter, Sally Jackson, was orphaned and taken in by her husband's brother Rich Jackson.