She was born on Christmas Day in Cockermouth, Cumberland, in 1771. Despite the early death of her mother, Dorothy, William and their three brothers had a happy childhood. When in 1783 their father died and the children were sent to live with various relatives, Wordsworth was sent alone to live with her aunt, Elizabeth Threlkeld, in Halifax, West Yorkshire. After she was able to be reunited with William, firstly at Racedown Lodge in Dorset in 1795 and afterwards (1797/98) at Alfoxden House in Somerset, they became inseparable companions. The pair lived in poverty at first, and would often beg for cast-off clothes from their friends.

She never married, and after William married Mary Hutchinson in 1802, she continued to live with them. She was by now 31 and thought of herself as too old for marriage. In 1829 she fell seriously ill and was to remain an invalid for the remainder of her life. She died at eighty-three in 1855 near Ambleside, having spent the past twenty years in, according to the biographer Richard Cavendish, “a deepening haze of senility”.

Wordsworth was primarily a diarist, and she also wrote poetry though without much interest in becoming an established poet. “I should detest the idea of setting myself up as an author,” she once wrote, “give Wm. the Pleasure of it.” She almost published her travel account with William to Scotland in 1803 Recollections of a Tour Made in Scotland, but a publisher was not found and it would not be published until 1874.

She wrote a very early account of an ascent of Scafell Pike in 1818, climbing the mountain in the company of her friend Mary Barker, Miss Barker’s maid, and two local people to act as guide and porter. Dorothy’s work was used in 1822 by her brother William, unattributed, in his popular guide book to the Lake District – and this was then copied by Harriet Martineau in her equally successful guide (in its fourth edition by 1876), but with attribution, if only to William Wordsworth. The account was quoted in other guidebooks as well. Consequently, this story was very widely read by the many visitors to the Lake District over more than half of the 19th century.

Her Grasmere Journal was published in 1897, edited by William Angus Knight. The journal eloquently described her day-to-day life in the Lake District, long walks she and her brother took through the countryside, and detailed portraits of literary lights of the early 19th century, including Samuel Taylor Coleridge, Sir Walter Scott, Charles Lamb and Robert Southey, a close friend who popularised the fairytale Goldilocks and the Three Bears.