FORGET THE SKIRT! It's mostly about her complete 180 in character than anything, it's just easier saying "AAAAGH! Carmelita's wearing a skirt, it's the end of the world!"
Seriously, the whole relationship thing between them is what caused it and bade her go "fullblown girl" instead of "Independent woman" like she used to be.
I guess I'm mostly mad about the fact that she blatantly ignores Sly trying to apologize and cares nothing about his entire family being in danger, she just keeps blaming him for something petty and refuses to see the big picture like, oh I don't know, Sly maybe never being born. Or never becoming a thief meaning they probably wouldn't have ever met. But no, let's just ignore that because Sly lied, big whoop.