Helen became a Christian as a medical student in Cambridge University in 1945. She continued to have strong links with the Cambridge Inter–Collegiate Christian Union and was designated as the “CICCU missionary” during the 1950s and 1960s. She built a combination hospital/training center in Ibambi in the early 1950s, then relocated to in Nebobongo, living in an old leprosy camp, where she built another hospital. After conflict with other staff at the hospital, she returned to England in 1958.
She returned to the Congo in 1960. In 1964 she was taken prisoner of rebel forces and she remained a prisoner for five months, enduring beatings and rapings. She left the Congo and headed back to England after her release but returned to the Congo in 1966 to assist in the rebuilding of the nation. She helped establish a new medical school and hospital (the other hospitals that she built were destroyed) and served there until she left in 1973. She helped many people from different countries, and helped them when needing food, and drink.
Since her return from Africa, she has had a worldwide ministry in speaking and writing. She was a plenary speaker at the Urbana Missions Convention three times. She is now retired and lives in Northern Ireland. Her life of service was portrayed in the 1989 film Mama Luka Comes Home. Her touching story about how the prayer of Ruth, 10–year–old African girl, for a hot water bottle to save a premature newborn baby after its mother had died has been widely forwarded by email. She survived rape and trial during the Congolese civil war in 1964 because of the intervention of the villagers she had helped previously.