John Brown of the Streatham Societyhas provided some more information about this little-known school and an advert from the St Leonard's Church Magazine April 1934.
Officially called Coronilla School for Girls and Kindergarten but also acted as a preparatory school for boys. It was founded by the Turner sisters in 1906 and it is not clear if first established in Streatham. By 1913 Misses Turner had taken up residence at 33-35 Gracedale Gardens in Streatham where they were operating a school which continued at this address until 1925 after which it moved to Earley Road. The School was run at this stage by just Miss D M Turner.
The school continued to operate in Eardley Road until 1938 when it moved to New Malden. Regular reports of prize givings and concerts by the school are given in the local press many of which were held at the Streatham Hall.