Interesting that she is listed as first name Amanda in 1900:
(index mis-spelled - it is Warrick on the record)

Name: Amanda Wassick
Home in 1900: Wilmington Ward 6, New Castle, Delaware
Age: 36
Estimated Birth Year: abt 1864
Birthplace: Maryland
Relationship to head-of-house: Head
Race: Black
Occupation: cook

Household Members: Name Age
Amanda Wassick 36
Ethel Wassick 11
Nathalie N Wassick 9

Name: Mary M Warrick
Age in 1910: 43
Estimated Birth Year: abt 1867
Birthplace: Maryland
Relation to Head of House: Head
Father's Birth Place: Maryland
Mother's Birth Place: Maryland
Home in 1910: Wilmington Ward 5, New Castle, Delaware
Marital Status: Widowed
Race: Mulatto
Gender: Female
Neighbors: View others on page
Household Members: Name Age
Mary M Warrick 43
Ethel Warrick 21
Natalie Warrick 18
Oscar Warrick 12
Amauda Warrick 6
Mary E Trusty 66
Lomia Backus 38
Walter Russell 34

Am wondering if she said her name was Mary Manda and they wrote M instead of A for Amanda in 1910. Oscar is missing in 1900 and she is listed with 6 children born 4 living instead of the 4 in 1910. She must have boarded young Oscar out, or sent him to live with relatives. There are several possibles in the 1900 census - do a check for children named Oscar listed as nephew or grandson - don't bother with surname (young children are often wrongly listed with the surname of the care provider)

In 1900 she is listed as married - in 1910 as widowed.

Oscar's middle name on Draft Registration is interesting. I wonder if it indicates anything about his mother's maiden name?

Name: Oscar Coppin Warrick
City: Wilmington
County: New Castle
State: Delaware
Birth Date: 13 Sep 1898
Race: Black
Roll: 1570932
DraftBoard: 4

listed living with his mother.

Hope this helps

Denise