Jessica Barden plays Nance O'Neil in Netflix's Monster: The Lizzie Borden Story. The real O'Neil was an American stage actress whose friendship with Lizzie Borden began years after the murder trial.
Who was Nance O'Neil?
Nance O'Neil was the stage name of Gertrude Lamson, an actress active from the 1890s through the early 20th century.
When did she meet Lizzie?
The real Lizzie Borden and O'Neil became acquainted around 1904, more than a decade after the 1892 murders and Lizzie's 1893 acquittal.
What does Monster change?
The Netflix series moves their meeting into the period before the murders and gives O'Neil a much larger role in Lizzie's trial story. That is a major dramatic change.
Were they romantically involved?
The nature of their friendship has been debated, but there is no definitive historical evidence establishing the romantic relationship portrayed or implied by the series.
Why does Nance matter?
Historically, O'Neil's friendship with Lizzie became important to Lizzie's later life and contributed to tension with Emma. The series uses that relationship as part of its larger story about fame, identity and public fascination.
Quick answer
Nance O'Neil was a real actress and later friend of Lizzie Borden. Their documented friendship began around 1904, not during Lizzie's murder trial.
Source
Fact-check note
This article distinguishes the Netflix dramatization from documented history. Lizzie Borden was acquitted in 1893; claims about guilt, private relationships, motives and events not established by surviving records are described as fictionalized or disputed rather than settled fact.
Netflix Tudum: The True Story · Netflix Tudum: Ending Explained · PEOPLE: Fact vs Fiction · PEOPLE: Emma/Lizzie Fact Check
Related: Nance O'Neil and Lizzie Borden: Their Real Friendship Timeline
Related: Lizzie and Emma Borden: The Real Sister Relationship Behind Monster
