Mary Lou Holder, 79, of North Huntingdon passed away on May 31, 2021. She was born February 19, 1942 in Johnstown, PA, the daughter of the late Francis and Margaret (Lidwell) Lux. Mary Lou attended Central Catholic High School in Johnstown, PA. She earned her RN at Temple University Hospital School of Nursing and then her BSN at California University of Pennsylvania. She then earned her Certified Professional in Health Care designation in 1990. Mary Lou worked for over 28 years at Frick Hospital in Mt. Pleasant, PA. Mary Lou was strongly guided by her Catholic faith and was an active member of Immaculate Conception Parish in Irwin, PA. She also volunteered for Meals on Wheels, Open Your Heart To A Senior, voting polls and helped with the U.S. Census. Mary Lou enjoyed the beach, bowling, card club, bingo and scratch off lottery tickets. She is survived by her husband of 57 years David Holder Sr.; her 3 sons David Holder Jr. and his wife, Diane, of North Huntingdon, PA, Mark Holder and his wife, Donna, of Chadds Ford, PA and Daniel Holder and his wife, Annette, of Greensburg, PA; three beloved granddaughters Sydney, Hayley and Kyley Holder; sister Janet Hanley of Johnstown, PA, sisters-in-law Loretta Lux of Dubois, PA and Kathy Barnhart, of Scottdale, PA as well as numerous nieces and nephews. In addition to her parents, she was predeceased by a sister Marjorie Lux and her brother Urban “Skip” Lux. Friends will be received 2-4 & 6-8 p.m. Thursday at Ott Funeral Home Inc 805 Pennsylvania Avenue Irwin. Parting prayers will be held 9:30 a.m. Friday in the funeral home followed by a 10 a.m. Mass of Christian Burial celebrated at Immaculate Conception Church. Interment will follow in Immaculate Conception Cemetery, North Huntingdon. In lieu of flowers, please consider a donation to Immaculate Conception Church, 308 Second Street, Irwin, PA 15642.