Today St Mary's Diocesan School is a Boarding and Day School catering to girls from Year 9 to Year 13 Girls. When it first opened in 1914 there were two teachers - Miss Marchant, who was also the Principal, and Miss Shepherd - along with 2 boarders, 10 day girls and 10 day boys.
The school roll climbed and the school outgrew the site quickly. The school board in 1917 purchased the current site of 11 and a half acres and arranged for new buildings to be built.
The building named after Miss Marchant, originally provided accommodation, but with the building of the new boarding houses it is now used as teaching space.
In its early days the Principals of St Mary's Diocesan were without doubt women of education, vision and courage. It is on foundations left by these women that St Mary's continues to thrive.
The building of the current chapel by Miss Roberton is one illustration of the qualities of these Principals. Miss Roberton, when she asked for a chapel to be built, was told there was no money - and to build it herself. What else was she to do but to do just that! Once the plans were drawn up it was all hands to work. Staff, students and others were all pressed into digging and laying the foundations, making bricks and fundraising. With this kind of determination it was not surprising that the chapel was opened in 1956.