In this situation I might take the "clueless" route and pretend like I had no idea why she texted Maca about me being there and didn't recognize the implied request to cancel. Play it like she MUST have just been texting Maca to double-check that I was still going, or something- because of course you have every right to be there and there's absolutely no reason for her to think that her opinion of you attending would at all affect your decision to go! If you can hide the completely understandable annoyance and put on a face of, "Well of course I'm here! Why wouldn't I be, silly!" then it makes her look like the idiot she is without you having to point it out to her. Win!
Pan Female, Hinge in a V between my mono (straight) husband, Monochrome and my poly (pan) partner, ThatGuyInBlack