I'm sorry Big mom, head to head with Kaido?

Maybe because she's a Yonkou? Since maybe normy cannon fodders can't really grasp the sheer difference between the strengths of the Yonkou?

Personally, I think he'd win but he would not do it easily and he'd be badly hurt during the fight. I know all of us fans like to speculate on the ranking amongst yonkos and such but even if she turns out t be the weakest, she is a freaking Yonko. She had to be much stronger than Katakuri and that says a lot