Sandra “Sandy” (Mader) Koski

Chatham - Sandra “Sandy” (Mader) Koski, 85, passed away peacefully at Regal Care in Harwich, MA on December 11, 2025.
She was the daughter of the late Frederick and Irma (Hamilton) Mader and was born and raised in Shrewsbury MA. Sandy was predeceased by her brother, Bradley Mader; her son, Brian Carlson; and her husband, John Koski Jr.
She is survived by her loving daughter, Jill, and her husband Brad, along with her cherished granddaughter, Jinean Erickson, all of Jefferson, MA. She also leaves behind her niece, Melanie Mader of Kentucky, as well as many cousins and dear friends.
Sandy attended school in Shrewsbury and later went on to college in Vermont. She married her former husband, Paul Carlson, and together they raised their children, Brian and Jill, in Paxton, where she lived for many years. She worked at Paxton Center School as a teacher’s aide while her children were young and later became a medical secretary.
In her later years, she married John Koski and moved to Chatham, where she became a familiar and friendly face working at a local shop. Sandy was the “Bookkeeper” for her husband Jack’s and Son Brian’s lobster Business on the boat named after her, The “Sandy K”. She stayed mostly on land but was known to go out and help when needed.
Sandy was deeply involved in her community. She volunteered her time helping elderly neighbors, assisted at local voting polls, the food pantry and was always ready to lend a hand to anyone—or any animal—in need.
She was an animal lover at heart, with a special affection for dogs. Her dog Seaweed brought her joy and companionship. Later she spoiled her son Brian’s dogs with “cookies” and lots of attention. When visiting her daughter Jill and granddaughter Jinean , she enjoyed all the various farm animals too.  She was always creative and crafty.  She spent countless hours knitting hats, mittens, lobster sweaters, and lovingly creating Christmas ornaments that became cherished keepsakes for family and friends. She also found peace and happiness in her garden, where her passion for flowers reflected her nurturing spirit and appreciation for life’s simple beauty. Flowers are blooming beautifully!
She will be remembered as a very caring person with a big heart and will be missed dearly by all who knew and loved her.
There will be a Joint burial with her husband Jack (John Koski) at the Bourne National Cemetery, on Friday May 1st 2026 At 1:15. There will also be a Celebration of Life for Sandy, Jack, and her son Brian Carlson at the VFW of Chatham MA on Saturday May 2nd 2026 from 2 to 4 pm. Light refreshments will be served.
In lieu of flowers donations can be made to the Alzheimer’s organization.