Molly doesn't get a ton of screen time in this film, but boy, does she make it count.
On the heels of losing one of her boys in the Battle of Hogwarts, and with Bellatrix aiming Killing Curses at Ginny, Molly is shooting (or spelling?) to kill. When she steps in to duel with Bellatrix, she even whips out a nasty, very-un-Molly word:
MOLLY: Not my daughter, you b****!
And then, as if that's not shocking enough, she legit kills Bellatrix. We know, we're shocked, too. But that will teach any Death Eaters to mess with the Weasleys again.