Speaker
The speaker is implied to be Shire herself. She is a writer reflecting on her difficult and painful memories of her home life as a child. She notes the way in which the loss of her father initiated a series of problems in her family. While not stated explicitly, she implies that both she and her sister suffered from abuse. She is strongly characterized by her desire to rewrite the past and alter these events, replacing them with love and care.
Sister
While never named, the speaker appears to be addressing the poem to her sister. This link seems fairly clear given that poem is dedicated to Shire's sister. This can also be gathered from the way she uses familiar family names like "mum" and also from the way in which she expresses concern about the abuse they endured as children. Shire shows a great deal of tenderness towards her sister in the text, referring to her affectionately as "kid" and telling her she will go back and fill their troubled history with love.
Father
Shire's father is unnamed but looms large over the entire poem. While never depicted overtly, Shire seems to hold some lingering positive memories of him, even though he left the family. Given his placement at the beginning and end of the poem, she clearly places a great deal of significance on his departure and wonders how things might have been different if he had stayed.
Step-Father
The step-father is shown to be the main antagonist in the poem. It is clear from his characterization that he is abusive. The speaker depicts various acts of violence that he was involved in, describing her bloody nose, his drinking, and his pushing her mother down the stairs. There is also an implication that he was sexually abusive. Where she speculates how things might have been if her father had stayed, she seems keenly aware of the massively traumatic impact her step-father definitively had on their lives.
Mother
Shire describes her mother as being a victim of her step-father's abuse, stating that she was pushed down the stairs and likely lost a pregnancy as a result.
