Forbes magazine ranked Spence ninth on its "America's Best Prep Schools" list in 2010.

She arranged for Edith Wharton, Helen Keller, and George Washington Carver to speak at the school.

[7] In a commencement address from an unknown year, Spence said that cultivating imagination was an important skill, since “sympathy, that great bond between human beings, is largely dependent on imagination—that is, upon the power of realizing the feelings and the circumstances of others so as to enable us to feel with and for them.”[7] The school has been located on East 91st Street since 1929.

In 2008, Spence acquired the adjoining Wanamaker-Munn townhouse on 90th street for use as it's Upper School facilities.

In a Worth magazine study, out of the 31,700 private and public high schools in the United States, Spence ranked the sixth most successful school in the country in placing its graduates in Harvard, Yale and Princeton.