Allen began her 48-year-long teaching career in the Hoboken School District as the principal of the elementary school. She then held the same role at Hoboken High School. Later in her career, Allen held the position of supervisor of the education of teachers at the Hoboken Normal and Training School.
At the age of 28, Allen became the vice-president of the New Jersey Teachers’ Association. In this role, she gained recognition as an advocate for the teachers’ retirement fund and issues related to teacher tenure. Allen was often thrust into the public eye and attracted a great deal of controversy because of her persistent and outspoken views.
In 1896, Allen’s hard work reached a pivotal climax. Senator John B. Vreeland of Morristown introduced a bill that provided half-pay annuity to teachers with 20 years of service who were no longer able to fulfill their roles as educators. This bill was financed by a one percent stoppage from the monthly salary of all those who elected to be considered by this law. Although the bill passed to become the first statewide teacher retirement law, there was still more work to be done. Membership for the bill was voluntary, and so, Allen set out through flyers, speeches, and newspaper campaigns to recruit as many members as possible. At the end of three months, Allen and her dedicated team managed to enroll more than half of the state’s teachers. She served as secretary of the Teachers’ Retirement Fund.