[2] She has also thrown batting practice to the Tampa Bay Rays, St. Louis Cardinals, Houston Astros, and New York Mets.
[3][4][5][6] Siegal is particularly interested and involved in sports gender equity, and noted for her success in coaching baseball in contexts that were previously male-only.
[9][10] Her grandfather and grandmother endowed the Cleveland College of Judaic Studies, now affiliated with Case Western Reserve University called the Laura and Alvin Siegal Lifelong Learning Program.
[16] In 2002, Siegal formed the Sparks, the first all-girl team to compete in a national "boys" baseball tournament.
[21][22] In 2011, at the age of 37, she was the first woman to throw batting practice to an MLB team, the Cleveland Indians during spring training.
"[25] She has also thrown batting practice to the Oakland Athletics, Tampa Bay Rays, St. Louis Cardinals, Houston Astros, and New York Mets.
[26][16] David Frost, the A’s assistant general manager, stated that they were thrilled that "Justine will be joining us for instructional league.... she brings with her a wealth of knowledge and expertise from years of playing, coaching, and teaching the game and all of our young players will benefit greatly from her time in camp.
In addition, Justine's duties included throwing bp, helping on-field practice, and charting the opposing pitchers.