In DC Comics Université Notre Dame des Ombres (French: Our Lady of the Shadows University) is a special university in France which was attended by the Crimson Fox twins and Dee Tyler (Phantom Lady).
Sandra Knight, the original Phantom Lady, became the dean of this School in her later years. She may have been an 'old girl' herself, as was the English girl Emma Knight, daughter of Sir John Knight, who went on to become an agent herself in the 1960s as Mrs. Emma Peel (see Action Comics Weekly #636).
Records of other graduates are still classified as "Top Secret", but given the school's location and 200 year history, it is possible that other female spies may well have passed through the doors of this fabled institution, including such as agents known under the code names of Sandra of the Secret Service, Mademoiselle Marie and Madame Zero. Obviously, given the nature of these ladies' line of work, any form of verification is impossible.
Action Comics Weekly #641 reveals that the future Diana Tyler, mother of the second Phantom Lady, was connected to the college until the mid-1960s, although she may well have been a tutor rather than a trainee agent.