The Unseeing by Anna Mazzola

A young woman with a child enters into a dependent relationship with a man who tosses her out in the cold when he finds a wealthy woman to marry. When he then takes her back suddenly and is then arrested for his former fiance's murder, Sarah is convicted of being an accomplice in the murder.
Sent to Newgate prison awaiting her death, Sarah's only hope lies in convincing a young attorney that she is innocent and her sentence should be commuted or acquitted. Edward is caught between wanting to believe her story and being used as a political pawn. This historical mystery takes us into the very real world of women in England who did whatever it took to survive and the political and societal disadvantage they faced. You, like Edward, will have the challenge of finding Sarah innocent or guilty as charged.