Gail Brandon is Rita Bennett's mother. Gail is a former schoolteacher who was fired by the school board due to "philosophical disagreements" (she disapproved of what she saw as the gradual acceptance of mediocrity in the way schools treated children and made her feelings well-known). She has extremely high standards, making her judgmental of her daughter and her grandchildren. She also distrusts Dexter, whom she believes to be a drug addict, and believes Rita is repeating her mistake with Paul by getting involved with another addict. Near the end of season two, her attitude causes Rita to break off all ties with her mother and force her to leave her home, not wanting her children to be exposed to her (like she was).

In season 3, Gail refused to attend Dexter and Rita's wedding, claiming that because she had started teaching again she was too busy. She did, however, send a scathing card expressing her hope that Rita's third marriage would be "the charm", though Rita is hiding that fact in stating that her mother means the third child. (it is also revealed that her surname, and therefore Rita's maiden name, is "Brandon").