Cecilia was the youngest daughter of Sir Cornelius Wessels, a farmer from the Bloemfontein area, who became Administrator of the Orange Free State towards the end of his life. Her exceptional vocal ability was discovered by the music mistress, Nina Reinecke, at the Oranje Meisieskool in Bloemfontein. Miss Reinecke took great care of her pupil's voice: Cecilia was 22 before she sang her first dramatic role in public. - Dorothy in Cellier's Dorothy of Haddon Hall.
After this demonstration of her talent, she was allowed to enter the South African College of Music in Cape Town, where Eveline Fincken took charge of her voice production, Pierre de Beer saw to her piano lessons, and Mina Freund gave her speech training (1917-20). In her final year she married Prof James Hutcheon, but he died shortly after their marriage and in 1922 her conservative father had no further objection to her continued vocal study at the RAM in London. In later years she liked to reminisce about the training she received from Frederick king, Raymond von Zur-Muehlen, Sir George Henschel, Albert Vissity and Georges Curelli, and to emphasize the part played in her development by the teaching and guidance of Sir Henry Wood. During her second year in London she sang at Sir Henry's Promenade Concerts in the Queen's Hall and achieved success in Tannhäuser, Il Trovatore and Carmen at the "Old Vic" Theatre.
In 1924 the death of her father recalled her to South Africa for a few months, an opportunity she utilised for a country-wide tour to display her growth as an artist. At the end of that year she returned to London for further study and accepted various engagements there and in other centres such as Bournemouth, Manchester, Ramsgate and Portsmouth. In December 1925 she again came to South Africa, this time for her marriage to Mr Ernest Beecroft, a mine-owner and mineralogist who had prospered in Zimbabwe (Southern Rhodesia). For the rest of their lives they lived in Cape Town - their large house provided for many years a social and artistic centre in which music lovers and friends could meet. Before their holiday tour of England and America in 1935, Cecilia toured in South Africa a few times and made several of her rare recordings for Columbia and HMV. In England Sir Thomas Beecham was impressed by the Wagnerian potential of her voice and broached the possibility of her singing Brünnhilde in a Covent Garden production of Siegfried. Personal considerations made this impossible at the time, but there was generally speaking no question of her neglecting opportunities overseas. She undertook about 25 journeys to Europe and England and achieved numerous successes in British theatres and concert halls, even though domestic ties excluded the possibility of binding contracts. A notable year was 1937 when she interpreted leading roles in Die Walküre and Cavalleria Rusticana and sang at the Wagner Festival held in the Opéra Comique in Paris under the direction of the Wagner specialist, Karl Elmendorff. From 1938 onwards, however, the main part of her career was concentrated in South Africa where she gradually rose to become a national figure. At the great Voortrekker Centenary Festival in Pretoria she was presented as an artist to a large cross-section of the Afrikaner nation. Concert tours, radio broadcasts and numerous public appearances (with, for example, the orchestras of Johannesburg, Cape Town and Durban) followed and contributed to the growing image of an almost legendary singer. She did not confine her appearances to the major centres and important national festivities such as the one already mentioned, or the visit of British royalty (1947), the inauguration of the Voortrekker Monument (1949), the Van Riebeeck Festival (1952), the inauguration of a State President (1961), or to cultural congresses, but sang even for tiny, isolated communities, possibly at the inauguration of a new organ, a charity concert, or a local jubilee festival. The question of remuneration was unimportant. From a compelling sense of mission, she resolutely undertook often arduous journeys into far-off regions, South-West Africa (now Namibia) or the former Rhodesias, to share her vocal gifts with appreciative people. A particularly apt example is afforded by the festival concert held in the Cango Caves near Oudtshoorn in 1967, when she substituted a star participant at very short notice, driving up by car at night to do so - at the age of 72! A striking aspect of her career is the incredible durability of her singing powers. In the year of her death (she was 75 at the time), she agreed to have the SABC (South African Broadcasting Corporation) record her voice in a programme including Wagner excerpts. With the exception of the pre-War recordings mentioned above, this had rarely been done. Besides this vocal phenomenon, she had other qualities like exceptionla breath control, and an almost elemental authority of a larger-than-life, romantic stature, a factor which contributed to mask the repetitiveness of her programmes. Taken in conjunction with her generous stage personality and the amusing naïveté of her (sophisticated) social etiquette, they serve to explain the warmth with which she is remembered.

On the occasion of the Jubilee of the Suid-Afrikaanse Akademie vir Wetenskap en Kuns (1959) she was awarded a commemorative medal in acknowledgement of her services to music in South Africa.