First of all, yes it's an LTR but hear me out.

I'm going to get right into it - I'll be giving her advice on something she knows I have knowledge and experience in, and she completely rejects all outside insight that conflicts with her opinion. She throws a condescending remark my way and becomes cold and unresponsive for the next few hours. Ever since we reached 6 months this kind of behaviour has become evident and at this point I'm getting sick and tired of it. She also has passingly mentioned that she doesn't have to put in as much effort as when the relationship started now that we're X months in. I have called her out on this once and made her cry, however I feel like I could be more in control of this situation.

I acknowledge that AWALT but this girl displays significantly less irrational behaviour than the average girl and thus I'm disappointed in seeing this kind of shit from her. I'm not a bitch who's going to let this keep going on without doing anything. I'd greatly appreciate some help that doesn't involve the obvious getting rid of her, although that will ultimately be the best solution.

TLDR: LTR gets defensive and disrespectful when questioned. HELP ME WHIP THIS BITCH