Born in London, England,[2] Griffith-Jones was the youngest of 11 children and daughter of a Welsh barrister Griffth Jones and Anne Laugharne Phillips, who were married in 1873.

(Her brother, John, was father of Mervyn Griffith-Jones, the prosecuting barrister [later judge] involved in the 1960 prosecution of Penguin Books for the publication of D. H. Lawrence's Lady Chatterley's Lover and the 1963 trial of Stephen Ward relating to the Profumo affair.

During World War I, she served as a welfare officer at a munitions factory in Wales, for which she was awarded an MBE.

When the school first opened in March 1925, it functioned from a disused supper shed[3] within the premises of the Tanglin Club.

At the time, many British expatriates living in Singapore had to send their children to Britain to attend boarding school at an early age.

Griffith-Jones saw the need to provide a British-style education in Singapore so that parents could postpone boarding school until their children were of an older age.

[5] She (Griffith-Jones) was largely responsible for European children being able to remain with their parents in Malaya several years longer than was possible in pre-war days.

In preparing the boys for English Preparatory Schools, she would teach them football, taking the forward line across the playing field and showing them how to pass the ball.

However, after consultation with the District Officer, it was established that the State Government would not alienate any further land to the British Forces based at the retreat.