Susan is the lesbian mother of Connor, a student of Watson Elementary where Lily also attends. She makes an appearance in "Schooled".
Both Susan and her girlfriend Pam are called up to the school because of the incident between Lily and their son, Connor, being threatened by Cam. She defends Mitchell in the meeting with the principal because he was trying to be nice. They are asked to have a play date with Lily and Connor to show them that they can all get along. During the play date Lily and Connor go to their room. Susan says that she is glad they were having the get-together because they are they only gay parents in the class. Mitchell agrees saying they should support one another. Susan asks what they do for a living, which after Cam says he's a homemaker Pam smirks at him. She invites Lily to come to their son's birthday party next week as well. Pam wants to leave after something Cam says and as they go to get their son, notice that the door is locked to Lily's room. The kids unlock the door after the parents talk to them.