Mary Lou Sienkiewicz (MacLean), age 85, of Bear, Delaware, passed away peacefully on August 18, 2026. Mary Lou was born in Detroit, Michigan and moved to Shamokin, Pennsylvania when she was 18 months old. She graduated from the former St. Stephens parochial school then was a graduate of the first graduating class from Our Lady of Lourdes High School.

Mary Lou met her future husband, Mark Sienkiewicz, at the Arena Skating Rink. They married in 1962 and shortly thereafter, moved to Bear, Delaware where they raised two wonderful sons, Mark Jr. and Matthew.

Mary Lou was a very accomplished woman. She worked on two Earthwatch projects. She worked on an official archeological dig in Ireland and was also part of a team that initiated the construction of a museum exhibit in Namibia.  Mary Lou also worked diligently in trying to pass the ERA.

Mary Lou took great pride in obtaining her pilot’s license for small aircraft. She would fly her family of four on vacation to Illinois and Texas. She also made three solo trips through Scotland.

While raising her sons, she worked at the Wilmington Post Office and later became a rural carrier.

When she was 50 years old, Mary Lou received a degree in Chemical Technology from Delaware Technical and Community College.

Mary Lou is also known for her deep love and affection for cats, animals and nature. She rescued many cats and provided a warm, loving retreat for cats over the years.

Mary Lou was predeceased by her parents George and Theresa (Yasisko) MacLean, grandmother Martha Chyzda, husband Mark Sr., son Mark Jr. and brother-in-law Bernard Pomidor.

Mary Lou is survived by her son Matthew and his wife Anna; grandchildren Joseph and Jacob; daughter-in-law Carolyn Sienkiewicz; sister Doris MacLean Pomidor and niece Dr. Mary Pomidor Eschelman and her husband Dr. David Eschelman; great nephew David Jr. and great niece Emma; niece Elizabeth and great nephew Julian Pomidor; nephew Bernard Pomidor and his wife Michelle Phillipi Pomidor.

A private Celebration of Life and burial will be held in September.