Q1. What are the three different phases mentioned in the poem?

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. She was rather happy and carefree in that stage.
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). This is the phase when the poet had loved hearing her mother's laughter and enjoyed her affection.
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 looking at the same photograph and recollecting her mother’s laughter. The loss of her mother makes her deeply sad. She has no words to describe the terrible pain of her mother’s death.