the thing is, strong doesn’t have to mean stubborn or bratty, and banter doesn’t have to be bickering. 

A strong character continues to fight in the face of adversity because it’s the right thing to do; a stubborn character fights all instruction, including actually good advice about how to survive or complete a task they need to complete, because someone else told them to do it. It’s not strong to fight tooth and nail against everything for absolutely no reason. (Also, an aside: liking pants as a female character doesn’t make you stronger than the women who wear skirts. that’s just internalized misogyny babes). 

Banter is witty back and forth between characters to build tension; bickering is when two characters fight over EVERYTHING for absolutely no reason and randomly inject sexual innuendo into every fight, even when it’s between two people with a wild power imbalance (say, a 1700 year old fae who can magically force people bonded to him to do whatever he says vs the dumbest 20something human in existence who spends all of her time flailing around ineffectually).