Born in Windsor, Allnutt studied at the Slade and at Bushey, and in Paris, where her sister Mabel Allnutt had also attended classes in the ateliers. By 1912, Emily had arrived in St Ives and shared Rose Lodge Studio, Wharf Road with artist friend Alice Hogarth NICHOLSON.
Her first exhibition locally was on Show Day 1912 at St Ives. The two women moved on to Gerrards Cross in 1915, and Allnutt did not return to live in St Ives until 1924, moving on to nearby Carbis Bay in 1931 (Tovey pp 188-9). She was a founder member of STISA and also a member of the Society of Women Artists SWA.