Margareta 'Rita' Martin began her photographic career in 1897 when she helped her elder sister Lallie Charles run her studio. In 1906 Rita opened her own studio. She worked in a similar studio to Charles and favoured presenting her portrait subjects in light colours against a white background. Amongst her most celebrated works are photographs of actresses such as Lily Elsie and Lily Brayton and child studies, particularly of Gladys Cooper's two children.
The few surviving negatives of Rita Martin and Lallie Charles were given to the National Portrait Gallery by their niece Lallie Charles Martin in 1994.