Sarah Jane McConnell was born in Ballykeel, Dromore, County Down, Ireland, the daughter of Trevor McConnell, a linen weaver, and his wife Jane, née Wallace.
She married Rainey Mills, a labourer, at the Cathedral Church of Christ the Redeemer in Dromore, and they moved to Belfast, where Rainety worked in Belfast's docks.
Their first child, Jane, was born at 80 Clementine Street, Belfast, in 1898, but died in infancy. A second daughter, also called Jane but known as Jean, was born in 1900. A third, Sarah Eveline, was born in 1903, and a fourth, Elizabeth, known as Lily, was born in 1906. An unnamed son was stillborn in 1909, by which time the family was living at 11 Coburg Street. Their sixth child, William, was born in 1910, a seventh, Annie, in 1913, and an eighth, a daughter, René, in 1917. Another unnamed son was stillborn in 1919.
Lily married Adam Gardiner in 1927, and they emigrated to Canada. Eveline married James Heslip in 1928. Sarah died of pneumonia at 45 St Kilda Street on 30 March 1934, and was buried at Dundonald Cemetery three days later.
Children
| Name | Birth | Death | Joined with |
| Jane Mills (1898-1899) | |||
| Jane Mills (1900-1986) | |||
| Sarah Eveline Mills (1903-1987) | |||
| Elizabeth Mills (1906-1973) | |||
| Unnamed Mills (1909-1909) | |||
| William Mills (1910-) | |||
| Annie Mills (1913-2004) | 16 May 1913 11 Coburn Street, Belfast, Ireland, United Kingdom | 2 February 2004 Belfast City Hospital, Belfast, Northern Ireland, United Kingdom (442 Ravenhill Road, Belfast) | John Logan Brown (1913-2009) |
| René Mills (1917-2011) | |||
| Unnamed Mills (1919-1919) | |||
Siblings
| Name | Birth | Death | Joined with |
| Eliza McConnell (1871-) | |||
| Mary McConnell (1873-) | |||
| Sarah Jane McConnell (1875-1934) | 26 May 1875 Ballykeel, Dromore, County Down, Ireland, United Kingdom | 30 March 1934 45 St Kilda Street, Belfast, Northern Ireland, United Kingdom | Rainey Mills (1876-1958) |
| Thomas McConnell (1875-) | |||
| Mary McConnell (1877-) | |||
| Trevor McConnell (1877-) | |||
| Gracy McConnell (1879-) | |||
| Ann McConnell (1879-) | |||
| Agnes McConnell (1883-) | |||