Mrs. Morgan is visibly stressed when Dave informs her that she "forgot" about the foreign exchange student they are hosting.
Mrs. Morgan is Dave and Teena's mother. She may be a social worker as she was talking on the phone about setting up a meeting regarding opening a new homeless shelter.
She is distressed by the fact that she was unaware that a foreign exchange student (according to Dave's fabrication) is going to be staying in their house and she had apparently forgotten.