Don't know if this is her, but, if so, may explain why you haven't been able to find her. From newspaperarchive.com-
The Ukiah Democrat, Aug 21, 1908, reports: "John Eglin, the well-known wholesale meat man, and Mrs. Ella C. Knapp were joined in the holy bond of matrimony Wednesday evening at the home of Mr. and Mrs. J. L. Dodge [of Mendocino]."
(Ukiah, CA) Dispatch-Democrat, Fri, Feb 22, 1924. MENDOCINO NOTES: John Eglin passed away at his home near Littleriver February 13. He was a native of Sutton on the Forst, Yorkshire, England, and was born April 22, 1838.. came to Mendocino Nov 1893.. purchased ranch south of Littleriver.. leaves a wife [unnamed] and four children, [among them] Mark A Eglin of Caspar. etc.
Ukiah Democrat, May 23, 1924: Ella C Eglin transferred a quitclaim deed to Mark A Eglin, dated Mar 27, 1924.
Ukiah Republican Press Wednesday, August 06, 1924, Ukiah, California: WANTED - Work by either hour, day of month. Address Mrs. Ella Eglin, care Peter Rudd.