DD9 has been difficult for basically forever and when she gets in a mood, watch out. She argued with people like a lawyer when she was 5. Dh has a much harder time with her and I noticed that it's because he stoops to her level and engages her, making accusations like "If you would just do....blah blah." Then he starts lecturing and it makes ME roll my eyes and I start imitating him under my breath (Blah, blah-blah, blah BLAH). Dh's droning on and engaging her gets DD even more worked up and argumentative. I tend to just tell her why she can't do something or why she did something wrong in a matter of fact way and let it go without lecturing or going on about it (and doling out a consequence if needed). DD is not nearly as argumentative or sassy with me as she is with Dh.
DD is getting to the point where I'm seeing some sarcasm. She doesn't really roll her eyes at me but she rolls her eyes when she's making fun of someone else's behavior. She has an uncanny ability to imitate people perfectly, complete with accent or whatever. She doesn't do this to make anyone feel bad...but people on TV or it might be a teacher at school and she imitates them later. It can be hilarious but I fear the teenage years if she is doing this already.