The three stanzas depict three different phases. What are they?

The first stanza refers to the childhood days of the poet’s mother when she was twelve years old or so. The stanza depicts a photograph of her mother when she went for a beach holiday with her cousins and uncle.

 The second stanza refers to the poet’s childhood days when her mother had become an adult. It depicts her mother recalling her childhood days while looking at the old photograph of hers (mentioned in the first stanza).

 In the last stanza, the poet’s adult life is described in which her mother is not with her anymore. She has been dead for almost twelve years. The stanza depicts the poet’s looking at the same photograph and recollecting her mother’s laughter. The loss of her mother puts her in utter grief. She has no words to describe the terrible pain of her mother’s death.