She was the eldest daughter of the four children of the Archdeacon of Derry, Thomas Bewley Monsell, and Jane Rae.
Initially a barrister, Conyngham Ellis left the profession to become a vicar, serving in Cranbourne, Windsor, Berkshire.
[4] A watercolour portrait of Ellis by Frederick William Burton is in the collections of the National Gallery of Ireland.
[1] Ellis' body of work consists of 68 flower and foliage water colour drawings.
Her studies were of common local plants, mostly those found in fields and hedgerows, such as primroses, bluebells, and violets.