There is confusion about this family so I'm going to try to clear up some misconceptions. The confusion stems from John Tyler Cadenhead marrying a mother and her daughter, and having children with each of them.
John Tyler Cadenhead (1 Jan 1875 - 29 July 1940) married about 1903, Mabel Clair Milam (14 Aug 1870 - 12 Aug 1955), divorced from Ernest George Walter Koehler of Dresden, Germany.
Mabel was the daughter of Laura and Robert Milam of Gadsden, Etowah County, Alabama.
Mabel married Ernest George Walter Koehler on 11 April 1899 in Birmingham, Jefferson County, Alabama. On the 1900 Census, Mabel and Ernest were living in Oshkosk, Winnebago County, Wisconsin. Daughter Minnie "Ruby" was born after the census was taken.
Their daughter, Minnie Laura A. Koehler was born 31 July 1900 in Oshkosh, Winnebago County, Wisconsin. She would later be known as Ruby Laura Koehler and Ruby Laura Cadenhead.
Mabel and John Tyler Cadenhead gave birth to daughter Lois Cadenhead about 1908-1909 and son John Cadenhead about 1913-1914.
Ruby Koehler appears on the 1910 census as daughter of Mabel Cadenhead, step-daughter of John Tyler Cadenhead. Young Lois Cadenhead also appears with her parents, John and Mabel, and older half-sister, Ruby. John and Mabel are listed as married seven years (his 1st marriage, her second).
On his WWI draft Registration, John Tyler Cadenhead claims his wife is "Rubie Laura Cadenhead" in 1918.
On the 1920 Census, John and Mabel appear as husband and wife, Ruby Cadenhead is listed as "daughter", the other children listed are Lois, 11, John, 6, Bob, 2 years 10 months.
John TylerCadenhead and Mabel Milam must have divorced at some point.
Mabel later married James Curry on 3 June 1922 in Enlsey, Jefferson County, Alabama, according to Alabama marriage reocrds.
On the 1930 Census, the family is listed as Charles Curry, with wife Mabel C., and step-son John Cadenhead. Listed in same household but as a separate family are John T. Cadenhead, 55, wife Rubie, 29, (first married at age 15), sons Robert, 13, Warren, 10, Leland, 6, and daughter Leona, 3 years, 11 months.
John Tyler Cadenhead died 29 July 1940 in Birmingham. Ruby is listed as his wife on his death certificate and in his obituary.
Also listed in his obituary are four sons, John Jr., Robert, Warren, and Leland Cadenhead, and daughters Mrs. A.J. (Lois) Thomason and Leona Cadenhead. Deceased family members aren't listed.
Ruby Laura Koehler Cadenhead died 21 October 1984 in Birmingham. Listed in her obituary are one daughter, Leona Cadenhead White; two sons, Leland and Rev. Robert Cadenhead; two brothers, John Cadenhead and Ernest Koehler William Koehler; and two sisters, Lois Cadenhead Thomason and Thea Koehler Terry. Deceased family members aren't listed.
Mabel Clair Milam died in 1955 as Mabel Clair Curry in Tampa, Hillsborough County, Florida. Her daughter, Lois Thomason also lived in Tampa.