Her father was in local government, serving as police magistrate and later as Secretary of the Colombo Municipal Council.

Her maternal grandfather, Frederick Jayatilaka, was an officer in the Ceylon Civil Service and had served as the District Judge of Kalutara.

Mollie Senanayake became the wife of the premier of Ceylon, when the country became an independent dominion of the British Commonwealth in 1948.

She hosted a dinner at the official residence, the Temple Trees, as part of the independence celebration.

[6] In the Sinhala film Nidahase Piya DS (2018), a biographical film about D. S. Senanayake, the character of Molly Dunuwila was played by actresses Thisuri Yuwanika (as a young woman) and her mother Susantha Chandramali (as an older woman).