Jane is the last of the four children of Charles Elgee, the son of Archdeacon John Elgee, a Wexford solicitor, and his wife Sarah (née Kingsbury). Her great-grandfather is an Italian who had come to Wexford in the 18th century. She has a special interest in Irish folktales, which she helps to gather. She marries Sir William Wilde on November 12, 1851, and they have three children, William Charles Kingsbury Wilde (1852–1899), Oscar Fingal O’Flahertie Wills Wilde (1854–1900), and Isola Francesca Emily Wilde (1857–1867).
Wilde, who is the niece of Charles Maturin, writes for the Young Ireland movement of the 1840s, publishing poems in The Nation under the pseudonym of “Speranza.” Her works include pro-Irish independence and anti-British writing. She is sometimes known as “Speranza of the Nation.” Charles Gavan Duffy is the editor when “Speranza” writes commentary calling for armed revolution in Ireland. The authorities at Dublin Castle shut down the paper and bring the editor to court. Duffy refuses to name who has written the offending article. “Speranza” reputedly stands up in court and claims responsibility for the article. The confession is ignored by the authorities. But in any event the newspaper is permanently shut down by the authorities.
Wilde is an early advocate of women’s rights, and campaigns for better education for women. She invites the suffragist Millicent Fawcett to her home to speak on female liberty. She praises the passing of the Married Women’s Property Act 1882, preventing women from having to enter marriage “as a bond slave, disenfranchised of all rights over her fortune.”
William Wilde is knighted in January 1864, but the family celebrations are short-lived, for in the same year Sir William and Lady Wilde are at the centre of a sensational Dublin court case regarding a young woman called Mary Travers, the daughter of a colleague of Sir William’s, who claims that he had seduced her and who then brings an action against Lady Wilde for libel. Mary Travers wins the case and costs of £2,000 are awarded against Lady Wilde. Then, in 1867, their daughter Isola dies of fever at the age of nine. In 1871 the two illegitimate daughters of Sir William are burned to death and in 1876 Sir William himself dies. The family discovers that he is virtually bankrupt.
Lady Wilde leaves Dublin for London in 1879, where she joins her two sons, Willie, a journalist, and Oscar, who is making a name for himself in literary circles. She lives with her older son in poverty, supplementing their meagre income by writing for fashionable magazines and producing books based on the researches of her late husband into Irish folklore.
Lady Wilde contracts bronchitis in January 1896 and, dying, asks for permission to see Oscar, who is in prison. Her request is refused. It is claimed that her “fetch” appears in Oscar’s prison cell as she dies at her home, 146 Oakley Street, Chelsea, on February 3, 1896. Willie Wilde, her older son, is penniless, so Oscar pays for her funeral, which is held on February 5, at Kensal Green Cemetery in London. A headstone proves too expensive and she is buried anonymously in common ground. A monument to her, in the form of a Celtic cross, is erected at Kensal Green Cemetery by the Oscar Wilde Society in 1999.