According to California birth records, the only mother’s maiden name common to a Yvonne, Eileen, and Brent is Brown. This gives Yvonne C. Webb born November 27, 1960 in Los Angeles County, Eileen M. Webb born May 15, 1962 in Orange County, CA, and either Brent L. Webb born September 18, 1964 in Los Angeles County or Brent E. Webb born April 24, 1966 in Yolo County, CA. I lean towards the Brent L. Webb option but don’t have enough to make it for sure.
Since Bert had step children, it stands to reason that his wife was older. It might be a reach (12 years older) but a possible match for a wife is Dolores K Webb (SSN 558-30-2319) born September 3, 1923 and died April 11, 2002 with a last address oin Midway City, Orange County, CA.
8US Public Records show a Dolores Patricia Webb aka Dolores P Lopez born on September 30 1931 in connection with Bert W Webb born May 2, 1935. She is also associated with Robert J Lopez born April 15, 1929 and Lorraine M Lopez who is listed as a step-daughter of Bert Webb in his obituary.