Sisco was a director of Textron, Chiquita Brands International, Neiman Marcus Group, K-Tron International, Newmont Mining, American Funds Series II, and Washington Mutual Investors Fund. She also served as chairman of the National Association of Corporate Directors, the Center for Corporate Leadership, and the Leadership Foundation of the International Women's Forum.
She was the first female director of the Metropolitan Washington Board of Trade and was inducted into the Washington Business Hall of Fame. She received the “Breaking the Glass Ceiling” award from the National Women's Economic Alliance. Sisco was treasurer of Reading Is Fundamental, president of the Washington Performing Arts Society and the Washington Ballet, and served under three presidents on advisory committees on vocational training and international trade.