The Edwin B. Douglas who was living in Modesto in 1930 was b. 1884 in Missouri.
I poked through the old city directories.
1931 has Mrs. Mary B. Douglas, clerk, living at 723 10th. She wasn't there in 1928, 1929, 1930, 1932, 1933, 1935.
I checked the reverse directoy. 723 10th is the "Tully Apartments". City directory data is usually 6 - 12 months out of date. It looks, from that one line, that she lived in Modesto for a year or so and was a widow. I have seen other women listed for 10 years in a row, the first "x" with their husband, the last "y" as "Mrs. Jane Smith, (wid. John)". If I had foun dthem lik ethat I'd bet money she was a widow. As it is, considering the year (the lowest point of the depression), Edwin may be dead, or may be off with the CCC or in a lumber camp somewhere. He may just not have been home at the time, and the drummer collecting data made the wrong assumption.