A hard-thrower underhand lefty, Applegren posted a 16–15 record for Rockford in her season debut and went 13-11 the next year, as part of a pitching rotation that included Carolyn Morris and Jean Cione.

[6] The Peaches, with Bill Allington at the helm, clinched the league title in 1945 with a 67–43 record and later defeated the Fort Wayne Daisies in the best-of-seven series, four to one games, behind a strong pitching effort from Morris (3-0) and the opportune hitting of Dorothy Kamenshek (6-for-21, .285).

[2][10][11] The first AAGPBL spring training outside the United States was held in 1947 in Havana, Cuba, as part of a plan to create an International League of Girls Baseball.

Muskegon (69-43) won a close pennant race with the Grand Rapids Chicks (65-47), having three of the top four leaders in earned run average with Sams (0.98), Applegren (1.06) and Warren (1.13), but failed in the first round of the playoffs dropping 3 of 4 games to the Racine Belles.

Applegren was a member of three Peaches champion teams (including her 1945 season), being glorified for the same feat by Eleanor Callow, Lois Florreich and Ruth Richard (all of them did it from 1948 through 1950).

[10] Following her baseball days, Applegren returned to Peoria and worked for Caterpillar Tractor Company as a data entry clerk for insurance benefits.

[2][18][19] In the early 1980s, a group of former members of the league led by June Peppas created the AAGPBL Players Association and lobbied to have the circuit recognized in the National Baseball Hall of Fame and Museum at Cooperstown, New York.