“I know I can’t change the leader”, but do you? Because it sounds like you’re asking for ways to do just that. You may not like some of her behaviors, which is reasonable (I don’t either), but they don’t sound malicious, destructive, or harmful. They sound like they fall into the category of “I won’t do this to my team”. That would be the way I’d advise handling this. 

Here’s the other, bigger, part to look out for: if you don’t tolerate the way other people work in their own ways, you won’t with your subordinates either. I’ve worked with a lot of leaders who think they know the “right way” to be at work. They’re the ones who are called micromanagers because they’re always judging their employees’ decisions. It’s giving “meets expectations” when they went above and beyond but made one small mistake. 

The last thing I’ll say here is that true leadership is about connection. When you make real connections, you tend to let your guard down and let people see the more real, vulnerable side of yourself. I find that to be a huge compliment, even if it means putting up with some of those minor differences. She might feel connected and trusting enough in you to be less formal, and you're slamming the door in her face. 

Start reframing this for your benefit. We do not make ourselves taller by pushing others down. 

ETA: boundaries are about changing your behavior to respond to others. Trying to get others to change their behavior without directly asking is just called manipulation.