"she will tear off her mind forg'd manacles"

Mind forg'd manacles is a quote from William Blake's (1757-1827) poem, London (1792).  The second stanza reads, 

In every cry of every Man,

In every Infant's cry of fear,

In every voice, in every ban,

The mind-forg'd manacles I hear.

The poem is a dark and bitter description of London's streets, as a place of misery and woe, of people ground down by poverty and oppression, in contrast to the rich owners of the Thames and of adjacent palaces.  The poem ends, appropriately to the current theme, with a young prostitute raging at her new born baby, and sending her own diseases back with her customers to their marital beds.  The final phrase, 'the marriage hearse', chimes perfectly with Lizzie and Fevvers' recent discussion of marriage as the end of woman's independence and sense of self, the end of her active life.

The same paragraph reads, 'the dolls' house doors will open'.  A Doll's House (1879) is a play by Norwegian Henrik Ibsen (1828-1906), whose chief protagonist is Nora, a young wife.  She secretly borrowed money from a male family friend when her husband was ill, and is paying it back from her own income.  As a woman she is not permitted to receive a loan without a male counter signatory, and the friend threatens to blackmail both her and her husband for the crime.  Desperate not to shame her husband, Nora contemplates suicide, but he discovers the truth and blames her for ruining his life and career.  When the friend repents and returns the evidence of the crime, Nora's husband forgives her, but she sees that he has never valued her for herself nor given her chance to discover her own self and leaves, telling him 'I have been your doll-wife, just as at home I was papa's doll-child'.  

With the opening of the dolls' house doors, Fevvers foresees women living freely to discover their own true selves in a new century.  Lizzie's response is less positive; her phrase, 'I see through a glass, darkly', is drawn from Corinthians 13:12.  The passage looks ahead to a perfect world to come, but warns that it has not yet come to be.