It looks like they were divorced-if you look at the D in Della and the D under status-they are the same.
On the 1920 I found a Herbert Lewis age 52 born in New York in Los Angeles Ca. The census image is really poor so it is hard to see what he did for a living. Here's the page number:
Name:Herbert Lewis Age:52 years Estimated birth year:1867 Birthplace:New York Race:White Home in 1920:Los Angeles, Los Angeles, California Home owned:View Image Sex:View Image Marital status:View Image Year of immigration:View Image Able to read & write:View Image Roll:T625_107 Page:8B ED:185 Image:0466
On the 1930 he is listed as Herbert O Lewis:
Name:Herbert O Lewis Age:62 years Estimated birth year:1867 Birthplace:New York Relation to Head-of-house:Head Race:White Home in 1930:Los Angeles, Los Angeles, California Occupation:View image Education:View image Military Service:View image Rent/home value:View image Age at first marriage:View image Parents' birthplace:View image Owned a radio:View image Image Source:Year: 1930; Census Place: Los Angeles, Los Angeles, California; Roll: T626_143; Page: 1B; Enumeration District: 263; Image: 0054.