Kate Kerwin is Ashley Kerwin’s mother. She divorced Ashley's father, Robert, after discovering he is gay and has cheated on her with another man (Christopher). Later, she gets together with Jeff Isaacs, Toby Isaacs' father, making Ashley and Toby stepsiblings. She and Robert have been on good terms since their divorce. She later attends her ex-husband's marriage to Christopher. She was portrayed by Maria Ricossa.
- Kate is one of seven wives to be cheated on by her husband. The other six were Mrs. Ryan, Christine Nelson, Daphne Hatzilakos, Mrs. Brooks, Helen Martin, and Mrs. Hollingsworth.
- Kate was very fond of Jimmy Brooks, and she always tries to invite him over for dinner. She was very upset when he was shot by Rick Murray in Time Stands Still (2).
- She disliked Craig Manning, due to his cheating on Ashley with Manny Santos, as seen in Voices Carry (1) and Voices Carry (2).
- She allowed Ashley to stay home in Season 3 as a result of her bad break-up with Craig.