Mary Ward, née King, was born in Ballylin, near Ferbane, County Offaly, Ireland, a daughter of the Rev. Henry King, a wealthy Anglo-Irish landowner, and his wife Harriette Lloyd. She and her sisters were educated at home and encouraged by their parents to study natural history. She became an avid amateur astronomer like her maternal cousin William Parsons, 3rd Earl of Rosse. She often visited him at his home at Birr Castle, Parsonstown (now Birr), where he built the "Leviathan of Parsonstown," then the world's largest reflecting telescope. Mary made sketches to chronicle each stage of the building process from 1840 to 1845, which were fine enough to help restore the telescope in the 21st century. Her father to bought her a microscope to study her insect collection, and she became an expert on its use. She made her own slides from slivers of ivory and prepared her own specimens. After Lord Rosse was named president of the Royal Society in 1848, Mary met many leading scientists on visits to his London home. In 1854, she married Henry William Ward, 5th Viscount Bangor, with whom she had eight children. After her marriage, she wrote books on science, beginning with A World of Wonders Revealed by the Microscope, reprinted numerous times between 1858 and 1880, Telescope Teachings (1859), and Entomology in Sport and in Earnest, co-authored with her friend Lady Jane Mahon (1859). She illustrated all her own works and many books and papers by other scientists. She also wrote articles for The Intellectual Observer. She died after being thrown from an early automobile being developed by Lord Rosse while driving on the road at Parsonstown, at age 42.