Mallory was a public school teacher.
She was initially romantically interested in Sam Seaborn, despite their extremely rocky start. Their relationship was a source of humor for her father, Leo McGarry, and First Lady Abigail Bartlet. She played blues harmonica. She and Sam drifted apart after the news broke about his relationship with Laurie, a law student who was also a high-end call girl. She dated a professional hockey player named Richard Andreychuk. Sometime before her father's death, she married and had a son. Mallory returned to the White House just before "Tomorrow" in order to wish the departing First Family all the best.