Mary Sylvia Hall Vadnais was born 1 November 1899 in Sublet, Cassia County, Idaho to Cumorah Angus Hall (1867-1918) and Elna Helene Christine Christensen (1877-1955) and died 1 May 1932 of unspecified causes. She married Earl Leon Vadnais (1896-1982) 28 July 1917 .
Children
| Name | Birth | Death | Joined with |
| Elna Rachel Vadnais (1918-1974) | |||
Siblings
| Name | Birth | Death | Joined with |
| Emma Almira Hall (1890-1891) | 22 November 1890 Stone, Oneida County, Idaho | 24 November 1891 Snowville, Box Elder County, Utah | |
| Name | Birth | Death | Joined with |
| William Carl Hall (1894-1945) | 29 September 1894 Mound Valley, Bannock County, Idaho | 30 January 1945 Preston, Franklin County, Idaho | Pearl Hansine Jensen (1898-1979) |
| Sylvester Angus Hall (1896-1972) | 24 February 1896 Elba, Cassia County, Idaho | 4 December 1972 Evanston, Uinta County, Wyoming | Emma Maude Sparks (1899-1991) |
| May Sylvia Hall (1899-1932) | 1 November 1899 Sublet, Cassia County, Idaho | 1 May 1932 | Earl Leon Vadnais (1896-1982) |
| Elna Rose Hall (1904-1991) | 27 June 1904 Niter, Caribou County, Idaho | 26 October 1991 North Bend, Coos County, Oregon | Ralph C Ashton (1893-1958) |
| Infant Hall (1910-1910) | 1910 Niter, Caribou County, Idaho | 1910 Niter, Caribou County, Idaho | |
| Ida Dorothy Hall (1914-1991) | 22 September 1914 Lewistown, Fergus County, Montana | 2 December 1991 Preston, Franklin County, Idaho | Parley Grant Byington (1902-1978) |