Before you were mine

Marilyn'

symbolism -Marilyn Monroe was a symbol of glamour and female sexuality. The speaker shows a deep admiration, with perhaps hints of jealousy, for her glamorous fun-loving mother. She is perhaps defending her mother's right to freedom, while Duffy explores how female sexuality is intrinsically  linked to a women's individual freedom.

Marilyn committed suicide and therefore this reference could potentially reflect the unhappiness associated with Duffy's birth and her mother's changing identity. 

Caesura- further emphasises the separation between her mother in the past and then during Duffy's childhood.

Duffy explores the realisation of a child that their presence in their parent's life may have come at a cost to the parent's personal happiness.

my loud, possessive yell'

my -possessive pronoun- creates a sense that the daughter owned the mother once she was born.

'loud, possessive' - adjective - she acknowledges that her presence could have been irritating and limited her mother's freedom because she was dependent on her.

Duffy suggests that her mother has sacrificed her own personal identity to raise her child, and now her identity is being a mother. The poet feels a sense of guilt, knowing her birth has changed her mother's life forever.

The poem explores the strong conventions of society women were expected to adhere during the 1950s, such as to remain at home, not work,  and raise their child. The poem explores the theme of female suppression and perhaps criticises the restrictive society women lived in , in the mid 1900s. 

where you sparkle and waltz and laugh before you were mine'

Duffy presents her mother's past as vibrant and full of life through the verbs 'sparkle', 'waltz',  and 'laugh' , which create a semantic field of joy and freedom, suggesting her carefree identity before motherhood. The verb sparkle conveys radiance and individuality, while waltz conveys elegance and movement, reinforcing the idea that the mother once had autonomy and excitement in her life.  However, the repeated phrase 'Before you were mine'  introduces a possessive tone, suggesting  that speaker is aware that her birth has altered her mothers identity, creating an underlying sense of guilt.  Structurally, this refrain emphasises the contrast between past freedom and present responsibility, highlighting the speaker's awareness that love has come at the cost of independence.

structure- 

the structure is very uniform and has four stanzas of five equal lines. This may reflect the initial structure of her mother's life, before entering motherhood, contrasting it with the flexibility and sacrifice she had to make after giving birth. Alternatively it could represent the intensely strong social conventions in place for women during the 1950s

Duffy explores the sacrifices women make when they become mother’s, including losing their inherent sense of self