LaValle was born as Mary Kostuch in Shakopee, Minnesota, on 17 November 1908. She was the eighth of 11 children born to Joseph and Magdalena Kostuch. As a child, she moved with her family to White Bear Lake, Minnesota, where her parents became farmers.
LaValle met her husband, Raymond, in Centreville as a teenager. The couple were married in 1926 and had their son, Leonard, the following year. They worked as vegetable farmers for many years, spending winters in Bradenton, Florida, and later purchasing a farm in Baudette, Minnesota, where they sold their produce to local stores.
Following their retirement, LaValle and her husband returned to White Bear Lake, where they would continue to grow vegetables in their back garden. LaValle also enjoyed cooking, baking, crocheting, embroidery, and sewing. She was widowed in 1991.
In 1993, LaValle moved into a nearby senior living facility where she lived independently in her apartment. She outlived her son Leonard, who died aged 80 in 2007.
LaValle died on 28 July 2019 at the age of 110 years, 253 days. She was survived by three grandchildren and four great-grandchildren.
LaValle’s age was verified by Stefan Maglov and validated by LongeviQuest on 29 July 2024.