Even with a Coburn name on the petition, however, the proposal passed and Colby College split into two separate educational establishments, one for men and one for women. Coburn was appointed to the committee to lead the new Women's Division. Despite her disapproval of the plan, she accepted the appointment to ensure Colby women received the best education possible. She pushed for women to be represented more in the college, and she became the first female Trustee of the college in 1911. She also served as the first President of the Colby Alumnae Association. She lobbied Colby to appoint its first female professor, Ninetta May Runnals, and was a strong advocate that Colby should provide better housing for its female students, which it eventually did.