You have to understand that this is a little girl who acted a lot older than she was. She's a lot smarter than to ruin her chance of becoming heir to the Fire Nation just for a some taunting. She's cunning and level-headed so she had to have thought about it. She knew with Lu Ten already dead and if Zuko died that she'd become the heir to the throne. She knew what was at risk but she she accepted them to tell Zuko. She had to taunt him so she wouldn't seem to soft, which is something she didn't like to be. She even said she was only telling him for his own good and suggests that he could run away and find a nice Earth Kingdom family to adopt him. It's pretty obvious, if you know Azula, that she wasn't just doing it to torment him because she's a lot smarter than that.

I always saw her as a bully. I wouldn't call her level headed though. Maybe as a kid.

Mix of both.

Both.

I also think it's both.