* Whenever Grandma shows she's not just a nice old lady.
** When Austin Bucks shows up to once again convince Grandma to sell her store (and joins her in her dress-up at the store to help convince her), she politely, but snarkily, says "Didn't help. Don't wanna listen."
** She usually handles Cousin Mel's attitude with grace, but that doesn't mean she's a pushover. When Cousin Mel starts yelling about Grandma not selling the store, Grandma almost tears her head off before switching back to her usual kindly demeanor. Grandma was also the first person to actually tell Mel off.
-->'''Grandma''': I'd tell ya to put a cork in it, you greedy money-grubber! But Grandmas shouldn't talk like that.
** She shows off her angry side to the rest of the family a while later. When she asked for help decorating, everyone except Jake gave her excuses and didn't lift a finger. When Grandma planned to bring some food to the local community center, Jake's dad says it's too late in the night. Grandma responds that if she'd gotten the help she had asked for, she would've left earlier. Her tone of voice and the look of anger on her face helps demonstrate that she doesn't take shit from ''any''one, even her own family.
* The summation at the end of every illegal thing Cousin Mel did throughout the movie, helped by it being Mel's LaserGuidedKarma and Jake having the satisfaction of seeing her squirm and dragging it out of her after all the shit she put him and Grandma through that year.