Margaret L. "Marnie" Danhauser (June 9, 1921 – January 6, 1987) was an American first basewoman who played from 1943 through 1948 in the All-American Girls Professional Baseball League.

The main promoter was Philip K. Wrigley, owner of the Chicago Cubs, who worried about the viability of Major League Baseball players during World War II decided to establish an alternate attraction.

The new league started with four teams, the Kenosha Comets, Racine Belles, Rockford Peaches and South Bend Blue Sox.

The pitching staff was led by Mary Nesbitt (26–11) and Joanne Winter (11–11), while Danhauser, Maddy English, Edythe Perlick and Claire Schillace could be counted on for their bats and solid defense.

During the season, the Belles again showed a great defense, notably by Danhauser at first, Kurys at second, English at third and Trezza at shortstop, while Irene Hickson caught and Perlick (LF), Schillace (CF) and Dapkus (RF) patrolled the outfield.

Then Danhauser, along with Dapkus, English, Hickson, Kurys, Perlick, Schillace and Winter, founding team members, were disappointment with the new location and would not make the move.