Mary E. Costello, of Burlington, passed away on February 25, 2026 at the age of 79.

Mary was the daughter of the late Leo and Geraldine E. (Callahan) Boulton. She grew up in Waltham and Watertown, where she singularly raised her family. Mary worked for the National Archives in Waltham for many years before her career at F. W. Webb in Burlington/Bedford. Mary will be remembered for her love of all Boston sports and her fierce sense of independence. 

Mary is survived by her daughters, Kristine Brown and her husband Timothy of Burlington, and Denise Porcello and her husband Ralph of Burlington. Mary is predeceased by her son John-Michael Costello. Mary was the niece of the late Edward and Joan Callahan, Thomas and Georgette Callahan, Marylou and Joseph Barnes, and John Callahan.  Mary’s pride and joy are her five grandchildren: Casey Porcello and her fiance Mark Melanson, Julia Doherty and her husband Kevin, Samantha Porcello, Shawn Brown and James Brown. Mary was present at their every recital, game, meet and celebration cheering loudly from the stands. 

Mary was a constant fixture at the Burlington Senior Center, where she enjoyed many activities and left behind many friends. Mary is also survived by her aunt Mary Callahan and many cousins who she regarded as siblings, particularly Kathleen Callahan- who was devoted to her, especially in her final days.

A funeral mass will be held at St. Margaret’s Church at  111 Winn St., Burlington on March 3, 2026 at 10am. 

In lieu of flowers, please consider making a donation in Mary’s name to Rosie's Place, a charity close to her heart, or the Burlington Senior Center - Council on Aging.