[3] She entered the All-American Girls Professional Baseball League in 1945 with the Rockford Peaches, playing for them one year before joining the Muskegon Lassies for the rest of her five-year career.

[4][5] When Fischer joined the expansion Lassies in 1946, the team's manager Buzz Boyle experimented with her at shortstop, where she was able to use her great throwing arm while sharing duties with Dorothy Stolze.

Muskegon clinched the championship with two days remaining on the regular schedule and advanced to the postseason, only to be defeated in the best-of-five first round by Racine, three games to one.

[4] In 1948 Fischer improved at shortstop, showing excellent range and lowering her error rate (36) compared to the previous year, raising her fielding average to .917.

[4] Fischer enjoyed a career year in 1949, her last season, when she became the best shortstop in the league with a .972 average and only 23 errors in 481 fielding chances while turning in 48 double plays.

[4] In a five-year career, Fischer posted a 34–37 record and a 2.40 ERA in 91 pitching appearances, while hitting a .223 average with 91 runs and 131 RBI in 345 games.