Marie married George Penny, also known as John, who had recently inherited his family's fishing business, John Penny & Sons, at the village of Ramea. Although John Penny & Sons was not doing well at the time of her marriage, Marie Penny began to play a central role in strengthening and directing the business. In recognition of changing times, she encouraged the company's transition from salted fish to fresh fish products, utilizing new freezing-plant technology. By 1948, business was booming, and Penny made a donation of $25,000 to the Liberal Party of Canada, which at the time was considering her husband for a candidacy in the upcoming federal election. In August 1949, George Penny was elected to Senate as a Liberal member, one of the first three Canadian Senate members from Newfoundland, but he died unexpectedly three months later while in Ottawa. After her husband's death, Marie Penny took full control of the business, assisted by her daughter Margaret. At the time, she had a fleet of ten fishing vessels and one supermarket. By the end of her career, she had directed the operations of two fishing companies, three fishing plants, and multiple retail stories. John Penny & Sons became one of the largest frozen-fish companies in Newfoundland, and received a number of substantial loans from the provincial government. Penny had several nicknames locally, including "Queen of the Fishing Fleet", "Queen of the Coast" and "Queen of the Ramea". She was once invited by the Governor General of Canada to meet Queen Elizabeth II at a dinner at Rideau Hall, an event which she considered one of the highlights of her life. Although it was common for merchant families in Newfoundland to live in the larger city of St. John's, Penny continued living at Ramea for the rest of her life. She entertained guests in her house and served Spanish sherry imported by her own ships. In 1967, Penny became the first female president of the Fisheries Council of Canada, a national organization of Canadian fishing companies. Canadian authorFarley Mowat once met Penny during a visit to Ramea, and later wrote about the encounter in his book Bay of Spirits.
Death
Penny died in 1970. After her death, Penny's daughter Margaret took over the company, operating it until John Penny & Sons was absorbed into Fishery Products International in 1982.