In 1924 this property was purchased from Mr Mortimer (Senior) to enable the St Anne’s Preparatory School to move to Hilton. St Anne’s Preparatory School was founded in Blackridge in 1921 and moved to Hilton on 13 August 1924. In February 1925 an impressive service of dedication was held when the choir, followed by the Bishop and five clergy, processed through the buildings singing ‘I Will Lift Up Mine Eyes Unto The Hills’ and ‘Now Thank We All Our God’.

By 1972 only 23 girls were in the preparatory section and the St Anne’s Nursery School was started in January 1972. In 1973 girls in Standard Five, the first Form One, moved up to the College. Once these girls moved into Standard 6 (Form Two) it was decided not to continue with Standard 5 and after fifty years of existence as a separate entity, the St Anne’s Preparatory School was no more! The nursery school continued in this building until June 1978, when it moved to new premises.

It was then decided to open a new House named after Miss Mollie Stone who had been Lady Warden of the College from 1942 to 1950. The House opened in 1982, with senior girls from other Houses volunteering to join the new House and with new girls in the junior forms thus making a total of 50 girls. It immediately became known as ‘Stonehenge’ or ‘Down in the Swamps’! Mollie Stone House was dedicated by Bishop Michael on Ascension Day – 20 May 1982.

In December 2002 renovations were done to the inside of the House to upgrade the accommodation for the girls and to provide single rooms for Form 6 girls and double rooms for Form 5 girls. These rooms were fitted with built-in study desks and shelves. A Study Room, with fitted desks and shelves, was created for use by the Form 4 girls to enable evening prep to be done in the House. The House now accommodated 52 girls.

In December 2005 further renovations were done. The accommodation for the Housemistress was upgraded and the Boardermistress was provided with much improved accommodation downstairs. There were also two new double rooms made available for Form 5 girls. In January 2006 the House accommodated 56 girls.