They will first appear in the 1920 census. By then Marie will be 28 and probably married.
In 1920 there is a Robert P. Ross in Coe, Isabella county, Michigan.
Name:Robert P Ross Age:30 years Estimated birth year:1889 Birthplace:Germany Race:White Home in 1920:Coe, Isabella, Michigan Page: 1A; ED: 196
Ida - wife, age 30, b. Mi. No children
From the 1930 census - Name:Robert Ross Age:41 years Estimated birth year:1888 Birthplace:Germany Relation to Head-of-house:Head Race:White Home in 1930:Pine River, Gratiot, Michigan Page: 3A; Enumeration District: 21
Add the following - Edwin R. - son, age 9, b. Mi. Gerald J. - son, age 5, b. Mi.