McCarthy's skills as a leader were put to the test when she allegedly fired an extra for abusing a child.
According to TMZ, the 42-year-old actress noticed that an extra was unable to keep her child quiet during the shoot. After the mother's scolding proved to be a distraction on set, a source says that McCartney saw her "jerk" her child up in the air by the wrist.
"The director IMMEDIATELY had PAs bounce the woman ... saying she wouldn't tolerate abuse on her set ... and that was that," TMZ reported.
There's no word yet from McCarthy's camp.
"Tammy," a comedy about a woman on a road trip with her alcoholic grandmother, stars McCarthy, Susan Sarandon, Allison Janney, Dan Aykroyd and Kathy Bates. It's due in theaters in the summer of 2014.
Swim Week Miami Beach 2014 [PHOTOS]