Mabel Evelyn Houze was born on December 22, 1936, in Detroit. She grew up in Mount Clemens, Michigan, the daughter of a restaurateur and a nurse.^[1] She attended college at the University of Michigan in Ann Arbor, earning a bachelor's degree in English in 1958, and pursued postgraduate studies at the University of Pittsburgh and the University of Pennsylvania.^[1]

She began her career as an English teacher in Pittsburgh and Philadelphia public schools, then worked as a vice principal and social worker.^[1] She married Robert Hubbard in 1964 and in 1970 they moved to Baltimore where he was assistant housing commissioner from 1970 to 1973 (and later a city official in Wilmington, Delaware). She taught English at Walbrook Senior High School, then left teaching to raise the couple's two sons.^[1]

As a stay-at-home parent, she was drawn to “learning for learning’s sake”^[2] and enrolled in law school at the University of Maryland, located in Baltimore, and took to it immediately—“She just loved it”, her son Robert told The Baltimore Sun.^[1] She graduated in 1975 and passed the bar the same year.^[1] She taught English for one more year, back at Walbrook High School in the 1975–1976 school year, then joined the office of the City Solicitor of Baltimore, first for a clerkship then as assistant city solicitor.^[2]

In 1978, she was appointed a master in the Juvenile and Domestic Relations Court of Baltimore, the first woman to hold the role.^[1] The appointment was also unusual for someone less than five years out of law school.^[3] Hubbard primarily dealt with juvenile cases, where her work was regarded as both fair and empathetic.^[3] In a 1986 interview she said she enjoyed that role, seeing low recidivism among the children whose cases she adjudicated: "I liked that job because most of the time a serious disciplinary intervention in the life of a wayward child makes a difference. Most kids don't come back."^[2] She continued there until 1981, when Governor Harry Hughes appointed her to the Maryland District Court for Baltimore City.^[4] Between this and her Master role, she is acknowledged as the first African American woman ever to become a judge in Maryland, having been excluded from the state bar entirely until 1950.^[3]

One of relatively few African-American judges in a city that was 70 percent African American, Hubbard was an “instant celebrity”, and though personally soft-spoken, recognized the significance of her place in the community and generally agreed to the many requests she received to speak to civic and school groups.^[3] She also felt a responsibility to serve as a mentor, particularly hiring a dozen African-American women as clerks over the years and helping them build their careers;^[3] Lisa Gladden became a state senator.^[1]

Four years after becoming a district court judge, Hubbard was promoted, again by Hughes, to the Circuit Court for Baltimore City.^[1] She was then elected to a 15-year term the following year.^[1] She served until 1999 when she retired.^[3]

Inducted into the Maryland Women's Hall of Fame in 2002, the citation emphasized "her deliberate judicial temperament, her agile mind and spicy, witty sayings called 'Hubbardisms'"^[3] using the latter to help manage a sometimes-tense criminal courtroom. “If that is true there is not a dog in Georgia” was one favorite saying; another statement of disbelief came in the pronouncement, "I've got to stop coming to court with my neon sign on my forehead saying 'Fool. Fool. Fool.' That way you'll be [less] inclined to spit in my face and tell me it's raining."^[1]

Robert Hubbard died in 1992. Mabel Hubbard died on 9 December 2006 at Levindale Hebrew Geriatric Center & Hospital in Baltimore, Maryland,^[5] of complications from a fall. She was 69.^[1]

The Women's Committee of the J. Franklyn Bourne Bar Association presents an annual Mabel Hubbard Legacy Award to an individual who has tirelessly served the local community.^[6]