Viceregal consort of Canada

The viceregal consort of Canada is the spouse of the serving governor general of Canada, assisting the viceroy with ceremonial and charitable work, accompanying him or her to official state occasions, and occasionally undertaking philanthropic work of their own. As the hostess of the royal and viceroyal residence in Ottawa, the consort, if female, is also known as the Chatelaine of Rideau Hall. This individual, who ranks third in the Canadian order of precedence, after the Canadian monarch and the governor general, is addressed as His or Her Excellency while their spouse is in office, and is made ex officio an Extraordinary Companion of the Order of Canada and a Knight or Dame of Justice of the Most Venerable Order of the Hospital of Saint John of Jerusalem.

Only once has the title of Chatelaine of Rideau Hall been held by someone who was not the spouse of the governor general—as Vincent Massey was a widower, his daughter-in-law, Lilias Massey, held the title and performed the official duties of the Chatelaine. Unlike a viceregal consort, however, Lilias Massey was not addressed as Her Excellency.

The position of the viceregal consort carries no official duties and receives no salary. However, consorts have held and do hold a prominent and visible position in the Canadian affairs of state, taking part in official occasions, such as the Speech From the Throne and Order of Canada investitures, and national celebrations, such as Canada Day events on Parliament Hill, as well as both welcoming foreign dignitaries to Canada and accompanying the governor general on state visits abroad. These practices evolved from the original role as the hostess of the royal and viceroyal residences in Ottawa (Rideau Hall) and Quebec City (La Citadelle), a tradition maintained only by female viceregal consorts, who oversee the planning of ceremonies and functions of state that take place at either of the official residences.

...
Wikipedia