Clara's joy is demonstrated through her laughter and uplifted spirit, as well as the reference to well-being in Diener's academic work, and the poem reflecting on fulfillment through gentle actions and love.
The question refers to the character Clara in a narrative, asking about the moment that showed she learned to feel joy. Clara's experience of joy can be inferred through her dialogue and actions. One example from the given references is when Amy, presumably Clara, felt happier and more spontaneous laughter than in years, symbolizing a breakthrough in her emotions. Another instance of Clara's joy is her uplifted spirit as she asks Tom to say something pleasant about God. This lightness and contentment indicate that she is experiencing a feeling of joy.
Additionally, the quotation from the poem "Woman's Progress" by Louisa Susanna Cheves McCord could reflect Clara's realization. The lines suggest that through gentle actions and labor of love, life grants fulfillment, possibly reflecting on Clara's growth towards feeling joy.