Berkshire - Clewer: High School
Clewer is an ecclesiastical parish within Windsor. The three eldest Sladden girls – May, Kathleen and Ethel – attended the High School there, May and Kathleen commencing in the autumn term 1895.
The school, known as the High School or St Stephen's College, was run by the Sisters of Mercy, an Anglican religious order of Augustinian nuns. It took the daughters of gentlemen and of clergymen (with a discount on fees), and student teachers The Community was founded in England in 1852 by Harriet Monsell (the first Superior), a clergy widow, and Thomas Thellusson Carter, a priest at St Andrew's Church, Clewer, Windsor. The purpose of the order was to help marginalised women – mainly single mothers, the homeless and sex trade workers – by providing them shelter and teaching them a trade. The work of the sisters expanded to include administering and working in orphanages, schools, convalescent hospitals, soup kitchens, and women's hostels.
The address on the Sladden girls' letters was St Margaret's House, Clewer, Berkshire; St Margaret's is thought to have been a boarding house at the school.