I have the following information:

Robert Johnson Yoak married Malinda Burrows on 10 December 1847. They had the following children:
Marcellus, born 25 November 1848
Hannah, born 25 Feb 1850
Mary E., born 25 Aug 1851
Elias, born 27 Feb 1853
Sara J., born 1 Jun 1854
Alpheus J, born 12 Jun 1856
Missouri Brown, born 1 Sep 1859
John B. Floyd, born 22 Mar 1961
Ruhala (or Mahala?), born 21 April 1863
Susanna Catherine, born 27 Sep 1867
James W., born 16 Nov 1969
Agnew T., born 12 Oct 1871

Robert Johnson Yoak was born 13 June 1820 (another source said 1824, but I believe the 1820 is correct) in Randolph County, Virginia (now W. VA) to Elias Yoak (b 3 Jan 1801) and Hannah B. Kelley Yoak. Robert died on 17 Feb 1895 in Grantsville (Calhoun County) West Virginia and is buried there in Pleasant Hill Cemetery. (I have a photo of his grave marker).

Malinda Burrows (also spelled Burroughs) was born 19 April 1932 in Lewis County, Virginia (now W. VA) to Archibald Burroughs and (?). Malinda died on 17 Feb 1880 in Grantsville (Calhoun County) West Virginia and is buried there in Pleasant Hill Cemetery. (I have a photo of her grave marker also).

After Malinda Burrow's death, Robert Johnson married Sara Jane Goldsmith. They had the following children:
Charles, born 6 Oct 1883
Effie, born 23 June 1885
Hester, born 6 Feb 1887
Erastus, born 13 Oct 1889

Sara Jane Goldsmith Yoak died in 1934 and ia also buried in
Pleasant Hill Cemetery.

Hope this helps. I have more info on who these children eventually married, etc. and also have some old family photos. You can contact me at mjsettles@yahoo.com if you need more info.