According to the info in the Mormon database (IGI) listed below:
Helen Essie Vanada Houseman Pedigree Birth:05 JAN 1895Point Washington, Walton, Florida Christening: Marriage:20 OCT 1920De Funiak Springs, Walton, Florida Death:11 DEC 1975 Burial:
Father:George Houseman Family Mother:Helena Brewer
Husband William Earnest Graham Pedigree
Birth:25 JUL 1879Ligonier, Noble, Indiana Christening: Marriage:20 OCT 1920De Funiak Springs, Walton, Florida Death:24 SEP 1963
It may be that she took back her maiden name after his death or the Social Security Index may list maiden or both maiden and married names for convenience.
At any rate notice at the end of my discussion I state: "If they are the same person..." I did not draw any conclusions since I had no hard facts, rather I left it open to possibility. Perhaps someone will later prove or disprove the possiblity.
As I get time I will check to see if I can find a Helen or Essie Graham in California.