Did some more sleuthing. Looks like Marguerite was the one with the 2 kids. CA BIRTH INDEX 7-31-1939 Barbara Ann KNIGHT, Los Angeles [found nothing further, as she probably m before 1960] 5-12-1947 Gregory Roy KNIGHT, Los Angeles [VESSEL is mom's name on both] 6-11-1967 Gregory m. Pamela DRAKE, Los Angeles It appear Gregory is still living in Spokane WA. The White Pages will give you address/phone. On a record for Greg I saw Marguerite & Pamela mentioned, so know this is right person.A fee to access these records, but his address/phone should suffice.
Found this...guess Barbara never married.
See more Roy Knight 23 May 1913 3 Jul 1988 Nine Mile Falls, Spokane, Washington; SS card iss: CA View Record Marguerite Knight 20 Jul 1914 Jul 1992 Nine Mile Falls, Spokane, Washington View Record Barbara Knight 31 Jul 1939 Mar 1984 Nine Mile Falls, Spokane, Washington