Along with the letter the Huberts sent a brief biography, which among other things, states that Mary (Marytje) and her children were permitted to join John Munro in Montreal, Canada in October 1778. They list the sons of John Munro and Mary Brouwer as Hugh, Cornelius, Henry, John, and William Johnson, and the daughters as Cornelia Pat(t)erson, Christine Mount, and Charlotte deLotbiniere. The Huberts also mention that the gravestones of John and Mary Munro were relocated to the United Empire Loyalist Shrine in the yard of Trinity Anglican Church in Riverside Heights, Morrisburg, west of Cornwall and just west of the Upper Canada village. "Their earthly remains lie under the newly created St. Lawrence seaway."
With respect to the fate of Loyalist wives who remained at home while their husbands were away during the Revolutionary War, those interested in further reading might try Janice Potter-MacKinnon, While the Women Only Wept: Loyalist Refugee Women in Eastern Ontario (McGill-Queen's Press, 1995)
Thanks to Carole Leishman for passing this along.
*Update March 27, 2014 - John Gearing, author of the forthcoming, Schenectady Genesis, Vol. 2, 1760-1798, by e-mail, informs me that the Huberts did not deposit the original letter of Mary (Brouwer) Munro with the Schenectady Historical Society. The Huberts had submitted a transcript of the letter to a "Connecticut genealogy society several decades ago," who in turn published the transcript in an issue of their newsletter. It was a copy of the Hubert's published transcript that was found in the Brouwer File at the Schenectady Historical Society. The original letter is located in the British Archives, and a microfilmed copy of the original is found in the Canadian Archives. The Schenectady Historical Society now has a photocopy of the microfilmed copy from the Canadian Archives which was provided by John Gearing. Thank you to John Gearing for the clarification.