She is first seen entering Mr. Fitz's classroom at the moment Aria brushes her fingers against his on the desk. They jump away from each other and Aria pretends to be asking him about an assignment then leaves allowing the two of them to chat.
Mrs. Welch chaperons the school homecoming dance with the other English teachers, including Ella and Ezra. She is eager to relieve Aria from her duty manning one of the game booths, so that she can operate the bean bag toss alone with Mr. Fitz, who is sporting a new haircut. Little does she know that she is interrupting an important conversation between Ezra and Aria by doing so. Later, Ezra makes a comment to Aria about his fresh haircut, sarcastically pointing out that he hadn't gotten it for Mrs. Welch to admire.
Ella, Ezra, and Mrs. Welch are seen lunching together in the cafeteria. (Some other unnamed teachers are sitting with them as well.) The three discuss an upcoming book event that Mr. Fitz invites his colleagues to attend with him. Mrs. Welch is very excited about Mr. Fitz's suggestion and convinces Ella to come along. Suddenly, Mrs. Welch and Ella are both witness to Paige McCullers' father denouncing Emily in the lunch room and watch admiringly as Mr. Fitz takes control of the situation.
Mrs. Welch returns in Let the Water Hold Me Down when Ezra Fitz offers her a spare ticket to a play. She runs into Aria and Holden there on a date then spots Ezra and gives him a hug. Afterwards, she talks to the kids again, telling them how refreshing it is to see young people attending such an event, then laments Ezra's unfortunate need to leave early.
Mrs. Welch does not appear at all during this season.
Season 1 (3/22)
Season 2 (1/25)