In 1990, she created the Siebert Entrepreneurial Philanthropic Plan, through which she shared half of her firm's profits from new securities underwriting with charities of the issuers' choices. The program offers buyers of new securities a chance to help charities in their communities. Through 2006, more than $5 million has been contributed through this program. She served as president of the New York Women's Agenda in 1998. During her term, NYWA developed a program advocating "Financial Literacy for Women", which continued until her death.