 Beckett was born in Casterton, Victoria, the daughter of Joseph Clifden Beckett (c1852-1936), a bank manager, and his wife Elizabeth Kate, née Brown (c1855-1934).Her grandfather was John Brown, a Scottish master builder who had designed and built Como House and its gardens in South Yarra, Victoria.Clarice was a boarder at Queen's College, Ballarat until 1903, before spending a year at Melbourne Church of England Girls' Grammar School.