At the end of My Mother at Sixty-six, the poet’s smile signifies an attempt to hide her sorrow and reassure her mother. Despite the deep sadness and fear she feels about her mother’s frailty and impending mortality, the smile is an act of concealment. It reflects the poet’s desire to mask her true emotions and provide comfort, both for her mother and herself, as she prepares to leave. This smile, though outwardly a gesture of calm, subtly conveys the poet’s internal conflict and the painful reality of impending loss.