Diane Petrin Flaherty, 60, of Barrington, NH (formerly of Essex Jct., VT) - passed away on August 18, 2022. Born on September 5, 1961, to Roger J. and Loretta (Vezina) Petrin, she grew up in Suncook, NH, attended Catholic primary schools, and graduated from Pembroke Academy in 1979. She continued her education at Saint Michael's College (SMC) in Colchester, VT, where she earned both a Bachelor's degree in Mathematics (magna cum laude) and a Master's degree in Education. Diane met the love of her life, Michael Flaherty, at SMC and they married on August 9, 1986 at St. Jean the Baptist Church in Allenstown, NH. Together they settled in Essex Jct., VT and raised three children: Patrick, Sarah, and Caraline. Diane spent thirty-two years dedicated to teaching math at Essex High School where she loved working with her fellow teachers and touched the lives of thousands of students. For many years she coached the Math League and served as Department Co-Chair. She was awarded Essex High School Teacher of the Year upon her retirement in 2015. Post-retirement, Diane and Michael moved to Barrington, NH to be closer to their families. She was generous with her time, volunteering at the local thrift shop benefiting hospice care, as well as working the local polls during elections. Diane was an extremely intelligent and creative person with an eye for detail. Over the years she developed hobbies in crafting, quilting, gardening, cooking, and interior design. She enjoyed word and jigsaw puzzles and had a knack of getting everyone involved. Diane was also known as an adept event planner, hosting holiday parties and family get-togethers. She loved day trips to the lake, ocean, and scenic drives in the mountains. Most of all, Diane enjoyed spending time with her children and their families whenever possible. Diane was a fighter, she navigated the challenge of pancreatic cancer with bravery, grace, and a positive attitude. There was little complaining during the year-and-a-half challenge. Additionally, she had the best interest of furthering pancreatic cancer research by participating in clinical trials. Right to the end, Diane's fighting spirit and generosity continued as she chose to participate in the New England Donor Services organ donation program. As a family, we feel very proud to know that even though she may not physically be here with us, she is still giving back to others. She was predeceased by her parents, brother in-law Roy Merrill, nephew Peter Caraway, and several cousins. She is survived by her husband, Michael, and their children: Patrick Flaherty of Winooski, VT, Sarah Yandow (Trevor) of Manchester, NH, and Caraline Flaherty (Chrissy) of Biddeford, ME. She is also survived by her siblings and their families: Denise LeBlanc (Marcel) of Hopkinton, Robert Petrin (Jeanne) of Northfield, Louise Schultz (Tim) of North Sutton, Ernest Petrin (Debbie) of Raymond, Cecile Merrill of Loudon, Michelle Caraway (Michael) of Pembroke, many in-laws, nieces, nephews, cousins, and her dear friend of more than forty years, Kimberly Murphy of Essex Jct., VT. The family would like to express their sincere appreciation to the staff of the Seacoast Cancer Center at Wentworth Douglass Hospital in Dover, NH, for providing comfort and unwavering care during her treatment; with special thanks to Dr. Henry Sonneborn, Caroline Kamau, APRN, all the outstanding nurses on the 2nd floor Infusion Room and in Inpatient care, the Integrative Therapy team, and to Dr. Agata Marszalek and the wonderful staff in Palliative care. A Mass of Christian Burial will be celebrated on Saturday, October 15, 2022 at 11:30am at the Holy Family Catholic Church in Essex Jct., VT with a lunch reception following. Committal service will be private burial held by the family later Saturday at the St. Michael's College - Merrill Cemetery. In lieu of flowers, donations can be made in the memory of Diane P. Flaherty to the Seacoast Cancer Center at https://giving.wdhospital.org/, selecting Seacoast Cancer Center in the drop-down options.