1940 and 1950 Census Findings

In the 1930 Census, both sisters Ruth and Gene were living in Chicago. They listed their ages as 25 for Ruth and 23 for Gene. This would mean Ruth was born in 1905. 

In the 1940 Census, Ruth is now married to Joseph Levin, so has his name, and is a mother of Max (18), Irving (16), Zena (10), and Joan (5). Now Ruth is listed as 37 years old, putting her birth year as 1903 and not 1905 as in the previous census.

In the 1950 Census, Ruth and Joseph now have only two kids living at home Joan (15), and Iris (5). Here Ruth listed a middle initial L. 

The source for this data is familysearch.org. A very well designed site by the Mormons.