She is first seen in "Mother Tucker". When she arrives to the Tucker-Pritchett house, Mitchell feels uncomfortable, due to Barb's inappropriate touching on him. Following Claire's advice, Mitchell tries to prove to Cameron that his mother is more than handsy but every time he tries to do it, Cameron is looking the other way. When finally realizing about the situation is when Mitchell is sticking his fanny for Barb to touch. Mitchell eventually confronts Cameron about his mother's inappropriate touching, not realizing that she is behind him. This hurts Barb's feeling before she finally realizes she has touched him inappropriately and apologizes, unfortunately this happens while Mitchell is in the bathtub.
She reappears in "ClosetCon '13", when Cameron, Mitchell and Lily visit Cam's birthplace Missouri. She is still touching Mitch and making him feel uncomfortable.
She and Merle nearly break up on their son's wedding day, but Jay and Gloria manage to reconcile the two.