Thanks for the lead. At first, I also thought that Cora and Ora might be the same person.
However, I found a link to a 1910 Census listing Cora Donaldson, widowed, and her two children living with Solomon & Martha Donaldson.
Name: Cora Donaldson
Age in 1910: 32
Birth Year: 1878
Home in 1910: Tobin, Scotland, Missouri
Relation to Head of House: Daughter
Marital Status: Widowed
Father's Name: Sol Donaldson
Father's Birthplace: Missouri
Mother's Name: Martha Donaldson
Mother's Birthplace: Missouri
Sol Donaldson 68
Martha Donaldson 65
Charles Donaldson 37
Cora Donaldson 32
Estle Donaldson 27
Clarence Dunn 10
Raleigh Dunn 4
If I understand correctly, since Ora was born in 1881 she would have just missed the 1880 Federal Census and most of the 1890 census was destroyed in a fire (therefore unavailable). By the time of the 1900 Federal Census she was already married to Henry Clay Chance, and she is still living with him at the time of the 1910 census.
I have a copy of the Memorial Card from her funeral. However, it lists no information about parents. Exact date of death was 7 Dec 1968, buried in Individual Mausoleum, Memphis Cemetery.