Milly was the eldest daughter and second child born to Sarah Unknown. Both her parents were born in Maryland. According to the 1880 US Census, her mother, Sarah, was a widow and employed as a servant. Milly was employed as a washerwoman and could read and write.
Milly's siblings were Peter, aged 19 and employed as a laborer; Milly, aged 17 and employed as a washerwoman; Willy, aged 10, and David, aged 5, who were both at school. David and Willy are listed as being Mulatto, while the rest of the family is listed as being Black. They lived on Market Street in the Georgetown section of the District of Columbia.
At the time of this profile's creation, there is no other source that lists Millie or any other available information.