The 1901 census lists one Mary Humphreys at Ingrave, aged 66 and born at Laindon in Essex. Additional information is available, but you have to pay for it.

The 1881 census, abstracted at The Church of Jesus Christ of Latter-day Saints, refers to a Mary Ann Humphreys, aged 46, born at Laindon (c.1835), and living at Common Road, Ingrave, with her husband Jonathan. He was aged 42, an agricultural labourer born at Navestock in Essex (c.1839). No children are mentioned.

Vaughan Williams noted 8 songs from Mrs Humphr[e]ys on 25 April 1904: Silvery Silvery; The Cambric Shirt; The Golden Glove; Poacher's Song; Tarry Trowsers; The Saucy Sailor Boy; I'm a Stranger (in this country), and Come Buy me a Hawk and a Hound.