Daughter of the Reverend Dr Richard Munkhouse and Fidelia Savage, Fidelia married Robert Keate Hill, a Captain of the East India Company's service on 24 July 1830 at St Dunstan in the West, London. They moved to Jamaica, where Hill took up a 'lucrative position', probably in 1831. They were accompanied by Fidelia's brother, Richard ('Thornton') Munkhouse, who died while they were in Jamaica.
Hill was then promised the position of Harbourmaster in the new colony of South Australia, but by the time they reached England in 1835 Thomas Lipson had already been appointed to the position. Nevertheless they made arrangements to proceed to South Australia, apparently on the understanding that Hill would be offered 'an appointment at salary equal to that of Harbour Master'; an appointment which was never made. Hill, described by fellow-officer William Pullen as a 'rough, good-humoured old fellow, very much given to drinking deep', came out as 3rd Officer on Light's brig Rapid, with his wife following on the Buffalo, in 1836. She claimed to be the first white woman to reach the site of Adelaide.
Their first dwelling in the new colony was a tent on the banks of the Torrens, and from there they moved into what must have been one of the first houses in Adelaide, in Hindley Street. Hill worked as Deputy Storekeeper for much of 1837, and was also sworn in as Constable. The couple moved to Port Adelaide in 1837. When Robert's employment as Deputy Storekeeper terminated he applied for the position of Chief Officer of the Pestonjee Bomanjee, and probably sailed from the colony in 1838.
Fidelia was living in Sydney when she published Poems and Recollections in 1840. She was the first woman to publish a book of poetry in Australia and the first to write about SA. It appears that her first husband died, and in 1842 she married Henry Howe, a Hobart draper, and eventually settled in Launceston, Tasmania.