Marion Westmore was a commercial transport passenger in the 24th century.
In 2328, the SS Kogin ferried her and her traveling companion Michael Westmore from Earth Colony II to Tellun system. Her passenger manifest was accessed by Lieutenant Commander Data aboard the USS Enterprise-D in 2370 by reviewing this data in the commercial transport database. (TNG: "Inheritance", okudagram)
This character was only mentioned in writing.
Marion Westmore is also the name of TNG make-up supervisor Michael Westmore's wife, and mother of Michael, Jr. and McKenzie Westmore.