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 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.