Let’s see there’s:
Hunters
Warrior Nun
Nuns with Guns…
What else?
Sister Mary Stigmata, aka the Penguin, in The Blues Brothers.
Does it have to be physical? Because the nun in Derry Girls is brutal with her sarcasm and wit. She kicks ass, defo.
Derry Girls is generally recommended for being frickin hilarious, BTW.
The nuns in "The Town"robbed a bank and had a shootout
Regina King’s character in HBO’s “Watchmen” dressed up as a nun to fight crime.
There wasn’t any direct contact between foot and posterior, but the “Bless us Reverend Mother, for we have sinned” scene in The Sound of Music was pretty kick-ass.
Sister Sarah in Nude Nuns With Big Guns Nude Nuns with Big Guns (2010) - IMDb
The tagline for the movie is “This sister is one bad mother”
SanVito speaks the truth. If you haven’t seen Derry Girls, do so at once. That is an order from Sister Michael.
The first thing I thought of, and kind of assumed the OP had in mind, is the recent miniseries Dracula(orig. BBC, now on Netflix).
Amanda Plummer was a badass nun in ‘Freejack’.
This thread has just brought a long forgotten memory of the song Nuns with Guns. In my mind’s ear, I was thinking Elvis Costello but it’s actually GE Smith (some might remember him from SNL). Beware, it’s an earworm.