She was president of the Royal College of Organists, the director of music at the church of St. Lawrence Jewry, and the founder of the London Organ Concerts Guide.
[4] Ennis attended Christ's Hospital school in Hertfordshire and subsequently Kingsway Further Education College.
Later, she was the director of music at the church of St. Lawrence Jewry in the City of London, beginning in 1985 and serving for 35 years until her death.
[4][12][13] Her subsequent concentration on her post at St Lawrence Jewry was partly to fit work around family life.
[3][6][8] For the 150th anniversary of the Royal College of Organists she welcomed HM the Queen and HRH the Duke of Edinburgh to a celebration at St. George’s Chapel, Windsor.