The Annagher woman, from Innishmore Park, was diagnosed with non small cell lung cancer after being troubled with a persistent cough and experiencing breathlessness towards the end of 2014.
Despite a course of chemotherapy followed by numerous sessions of radiotherapy as part of a trial, the 46-year-old grandmother was advised the cancer had spread to her other lung, liver, bones and lymphnodes and she was given the devastating news that her condition was terminal.
In January, she launched an urgent appeal to fund medical treatment costing £25,000 in the hope that it could save her life.
Tragically, she passed away at hospital on July 3 surrounded by her family.
Karen was the daughter of Marie and the late Kevin, and mother of Ciaran and Brian. She had three grandchildren and was engaged to be married to fiance Chris.
Family friend Nuala Donnelly said: “Karen had a real fighting spirit, very much so, for her family.”
Her funeral was held at St Mary and St Joseph’s Church.