Harriet Isabel Lamont, known by her second name, was born on 20 Sep 1872 at 'Braemar', North Esk River, to James Brough Lamont (1842-1916) and Margaret Elizabeth Allan (1844-1916). She had a twin sister Margaret and four younger siblings: Jessie Allan (Dolly), 1874-1904; Gertrude Fanny, 1876-1882; Rose James, 1878-1882 and Boronia Sarah Allan, 1883-1886. Isabel and her sister Dolly were sopranos in the Tasmanian Exhibition Choir in 1891-92.
On 12 Dec 1899 Isabel married Alfred Charles Cowle at the beautifully decorated St John's Church, Launceston. Her sisters Margaret and Jessie were bridesmaids. After the wedding the couple left on the Coogee for a honeymoon in Melbourne. They had two children: Inez Lamont, born 5 Dec 1900 and Isabel Lamont, born 13 Jan 1904. Harriet Isabel Cowle died on 29 Mar 1920 aged 42. She was buried at Carr Villa in Section F 336 with her husband who had died on 26 Oct 1914.