Agnes Monk was the wife of Jack Monk and mother of Ambrose and Adrian. Little is known about her apart from the fact that she was emotionally distant and had difficulty expressing affection towards her husband and sons. She did not like being hugged, preferring to shake hands instead. She was also something of a control freak, telling Adrian not to share his school lunch with anyone and to sit near the fire doors. She made her sons practice laughing to make them seem normal but did not succeed. According to Adrian, she never even pretended to love him. She once left a note in his lunchbox saying that "your father is driving me crazy".
Agnes died as the result of an unspecified illness in 1994. Her only appearance in the series was in a flashback in "Mr. Monk and Little Monk" where she was played by Rose Abdoo.