I looked up Leroy and Harriett on the 1920 census in Sc and it said that her father was born Louisiana and mother born Alabama.
I found your Harriett and family on the 1900 census living in Birmingham city, Jefferson, Alabama
Name: Harriet F Mc Knight Titles: Residence: Birmingham city, Jefferson, Alabama Birth Date: Jul 1889 Birthplace: Alabama Relationship to Head-of-Household: Daughter Spouse Name: Spouse Titles: Spouse Birth Place: Father Name: Robert Mc Knight Father Titles: Father Birthplace: Louisiana Mother Name: Harriet M Mc Knight Mother Titles: Mother Birthplace: Alabama Race or Color (expanded): White Head-of-household Name: Robert Mc Knight Gender: Female Marital Status: Single Years Married: Estimated Marriage Year: Mother How Many Children: Number Living Children: Immigration Year: Enumeration District: 0138 Sheet Number and Letter: 20A Household ID: 424 Reference Number: 11 GSU Film Number: 1240022 Image Number: 00875 Household Gender Age ParentRobert Mc KnightM b La Nov 1858 age 41 parents b Nc ParentHarriet M Mc KnightF b Al Feb 1859 age 41 parents b Sc Married 17yrs Mary S Mc KnightF b Al Mar 1887 age 13 Harriet F Mc KnightF b Al July 1889 age 10 Elizabeth A Mc KnightF b Al July 1891 age 8
On 1910 Father and 2 daughters are still living Birmingham Ward 8, Jefferson, Alabama
Name: Harriet Mc Knight Birthplace: Alabama Relationship to Head of Household: Daughter Residence: Birmingham Ward 8, Jefferson, Alabama Marital Status: Single Race : White Gender: Female Immigration Year: Father's Birthplace: Louisiana Mother's Birthplace: Louisiana Family Number: 91 Page Number: 7 Household Gender Age ParentRobert Mc KnightM 57y Harriet Mc KnightF 20y Elizabeth Mc KnightF 18y