Dorothy was born on 17 February 1755, probably at Woodford, Essex as the youngest of five children of Thomas Kilner (1719–1804), public servant and landowner, and his wife, Frances, née Ayscough (1718–1768).

Predeceased by most of her family, Dorothy became an invalid after a back injury in 1817, and her mind became unhinged in her later years, but she was looked after by her niece Frances and her grand-niece Maria.

[1] Dorothy Kilner published anonymously at first and then under the successive pseudonyms of M. P. and Mary Pelham, in line with general practice for female authors in that period.

The book concludes: "From this fatal accident it is to be hoped, that every body will learn to be extremely cautious not to leave candles burning near linen, nor, indeed, anywhere, without constantly watching, that they may not do mischief."

Copies of the books of Dorothy and Mary Ann were found long after their deaths in a trunk in their Maryland Point home.

The Life and Perambulation of a Mouse, for instance, reappeared in 1870 in a collection edited by Charlotte M. Yonge, entitled A Storehouse of Stories.