In the novel Cat Among the Pigeons, Mary Vyse is one of the pupils at Meadowbank School for Girls. While marking Mary's essay, Miss Bulstrode notes that although she is academically gifted, of scholarship class and with a wonderful retentive memory. But she is also very dull.
The above last fact also makes her unlikely to be the same Mary who is among the three "giglers" that Adam Goodman reports that he has befriended.