Dude is an asshole. Can't do that under any circumstances...although I've been tempted.
She clearly instigates it...turns and talks smack to him, then takes a swipe. And, she's no small girl. Probably just another perpetually drunk potty-mouthed bitch with an attitude of entitlement.
But, still, can't hit her under any circumstances.
Best defense in that case is just to wait a few years, let her continue to get drunk and fat, let her squeeze out a few pups and settle into a motor home with her abusive drunk husband, and then follow her to Wal-Mart and make fun of her.