Which of Darwin's daughters died at age 10?

Darwin’s daughter Anne Darwin died at the age of 10.

Anne Elizabeth Darwin, whom the family called Annie, was born on 2 March 1841. She was the second child and eldest daughter of Charles Darwin and Emma Wedgwood. The Darwin children were closely involved in family life at Down House, and Anne was especially remembered as a lively and much-loved child.

In 1849, Anne contracted scarlet fever along with two of her sisters. Her health declined afterward, and some historians have suggested that tuberculosis may also have contributed to her illness. Seeking treatment, Charles Darwin took her to Great Malvern in Worcestershire, a spa town known for its water-cure therapies.

Anne died on 23 April 1851 at Montreal House in Great Malvern, just weeks after her tenth birthday. She was buried in the churchyard of Great Malvern Priory. Her death deeply affected both parents and has often been discussed in biographies of Darwin, particularly in connection with his changing views on religion and suffering.