Look, she's obviously doubting if she's male or transfem. Since she lives in a patriarchal society, her true self will be repressed by society.
He's definitely shown some egg behaviours, but addressing someone respectfully means addressing them as the gender they tell you they are, no matter how you read them. "I'm calling her she because I think she's an egg" is just as disrespectful as "I'm calling him he because that's how the doctor assigned him at birth." If there's an "I think I might be a girl" arc later, I will be the first to cheer, but until then, Kaoru is the boy he says he is.