Hi,
According to the 1880 census Matilda was 2 years younger than Calvin. ...
Here is the source citation. I have the image if you want it. ~Cyd Rawls

1880 United States Federal Census
Name: C. C. Beard
Home in 1880: Brandywine, Claiborne, Mississippi
Age: 23
Estimated birth year: abt 1857
Birthplace: Mississippi
Relation to head-of-household: Self (Head)
Spouse's name: M. J. Beard
Father's birthplace: Mississippi
Mother's birthplace: Mississippi
Neighbors: View others on page
Occupation: Farmer
Marital Status: Married
Race: White
Gender: Male
Household Members:
Name Age
C. C. Beard 23
M. J. Beard 21
Jasper Beard 3
Moss Beard 1
Frank Newman 17