Karl and Jenny Marx had the following seven children, in chronological order:
Jenny Caroline  (1 May 1844 – 11 January 1883).
Married Charles Longuet in 1872.
She was a socialist activist.
She wrote for the socialist press in France in the 1860s, most importantly in exposing British treatment of Fenian revolutionaries in Ireland.
She died of bladder cancer, aged 38.

Jenny Laura (26 September 1845 – 26 November 1911), born in Brussels, Belgium.
Married Paul Lafargue in 1868.
She was a socialist activist.
Laura and her husband did decades of political work together, translating Marx's work into French, and spreading Marxism in France and Spain.
She died in a suicide pact with her husband.
She was 66.

Charles Louis Henri Edgar (3 February 1847 in Brussels – 6 May 1855), Mush to family and friends, named for his uncle Edgar, the brother of Jenny von Westphalen.
He died, aged 8.

Henry Edward Guy (5 September 1849 – 19 November 1850), Guido to family and friends, born and died at London.

Jenny Eveline Frances ("Franziska"; 28 March 1851 – 14 April 1852)
Jenny Julia Eleanor (16 January 1855 – 31 March 1898), born in London.
She was a socialist activist.
She committed suicide at the age of 43 by poisoning herself with prussic acid after discovering that her long-term partner Edward Aveling secretly married a young actress named Eva Frye in June 1897.

An unnamed child, born and died 6 July 1857 in London.
Karl and Jenny Marx had the following seven children, in chronological order:
Jenny Caroline  (1 May 1844 – 11 January 1883). Married Charles Longuet in 1872. She was a socialist activist. She wrote for the socialist press in France in the 1860s, most importantly in exposing British treatment of Fenian revolutionaries in Ireland. She died of bladder cancer, aged 38.
Jenny Laura (26 September 1845 – 26 November 1911), born in Brussels, Belgium. Married Paul Lafargue in 1868. She was a socialist activist. Laura and her husband did decades of political work together, translating Marx's work into French, and spreading Marxism in France and Spain. She died in a suicide pact with her husband. She was 66.
Charles Louis Henri Edgar (3 February 1847 in Brussels – 6 May 1855), Mush to family and friends, named for his uncle Edgar, the brother of Jenny von Westphalen. He died, aged 8.
Henry Edward Guy (5 September 1849 – 19 November 1850), Guido to family and friends, born and died at London.
Jenny Eveline Frances ("Franziska"; 28 March 1851 – 14 April 1852)
Jenny Julia Eleanor (16 January 1855 – 31 March 1898), born in London. She was a socialist activist. She committed suicide at the age of 43 by poisoning herself with prussic acid after discovering that her long-term partner Edward Aveling secretly married a young actress named Eva Frye in June 1897.
An unnamed child, born and died 6 July 1857 in London.
Jenny von Westphalen