Here's a map from 1907. John Bavington Jones in his book Dover - A Perambulation of the Town, Port and Fortress (which incidentally was published in the same year) says of the site ......
....... the houses on the south side, known as Connaught Park Gardens, numbering but twelve, arranged in six pairs.
On the map you can clearly see the houses. Perhaps a good place to start would be Dover Reference Library. The original of the map is there, as are Kelly's Guides and probably newspaper clippings relating to the Girls Grammar School.
I'd also strongly recommend The Life and Times of a Dovorian by Lilian Kay, a former headmistress of DGGS. This book contains a wealth of information and memories and should also be available at the Reference Library.
