Thanks for those dates, Sandra.
Going back to the 1900 census records it does seem odd that Abigail would become Mary A but it appears her sister Lovina appeared as Mary L on an earlier census. It is also odd she would be shown as Boarder rather than Sister - but I also have a case where a son is the informant for his mother's death and is shown as "Occupant" rather than "Son".
Perhaps in 1900 James and (Mary) Abigail were separated but James did not want this known.
The 1910 census for Mendicino Township, Healdsburg City, California shows James L Cirby age 41 born California, parents born Kentucky and Illinois, with wife Clara M age 35 born California (other records suggest maiden name Roscoe) and children William age 14, Gerald age 8 and Elmer age 1 all born California.
The James L Kirby on the 1900 census with wife Abbie shows his parents as born Illinois and Illinois.
Of course, there could be two men named James L Kirby/Cirby both born about 1869 both with sons named William L born about 1896 - but it seems like a big coincidence.
James and Clara are recorded as being married for 16 years and Clara as having 3 children, but a document titled "McMillan Genealogy and History" on the North America, Family Histories, 1500-2000 Index states that Clara M Roscoe was married to James S Cirby on 19 November 1905 in Sacramento and that their Post office address in 1908 was Sanoma.
The 1930 census for Rohnerville Township in Humboldt County suggests that James L Cirby age 61 and wife Clara M age 55 were married when they were 36 and 25 indicating marriage in 1905 for James (but 1900 for Clara?).
I wonder what happened to daughter Mary B Kirby/Cirby born 1898?