Here's Margaret's marriage license with her parents names. And the 1920 Census. As you can see they are all white. Also all their neighbors are white.
Margaret Moorhouse Cook
in the Michigan, U.S., Marriage Records, 1867-1952
Name Margaret Moorhouse Cook
Gender Female
Race White
Age 34
Birth Date abt 1918
Birth Place Ludington, Michigan
Marriage License Place Wayne
Marriage Date 17 May 1952
Marriage Place Detroit, Wayne, Michigan, USA
Residence Place Detroit, Michigan
Father
Wesley J Cook
Mother
Sarah E Moorhouse
Spouse
Gerhardt C Peschel
Margarat Cook
in the 1920 United States Federal Census
Name Margarat Cook
[Margaret Cook]
Age 1
Birth Year abt 1919
Birthplace Michigan
Home in 1920 Scottville, Mason, Michigan
Street East State Street
Residence Date 1920
Race White
Gender Female
Relation to Head of House Daughter
Marital Status Single
Father's Name Wesley J Cook
Father's Birthplace Michigan
Mother's Name Sarah E Cook
Mother's Birthplace England
Name Wesley J Cook
Age 39
Birth Year abt 1881
Birthplace Michigan
Home in 1920 Scottville, Mason, Michigan
Street East State Street
Residence Date 1920
Race White
Gender Male
Relation to Head of House Head
Marital Status Married
Spouse's Name Sarah E Cook
Father's Birthplace Canada
Mother's Birthplace USA
Name Sarah E Cook
Age 40
Birth Year abt 1880
Birthplace England
Home in 1920 Scottville, Mason, Michigan
Street East State Street
Residence Date 1920
Race White
Gender Female
Immigration Year 1887
Relation to Head of House Wife
Marital Status Married
Spouse's Name Wesley J Cook
Father's Birthplace England
Mother's Birthplace England