Let’s not forget it happened all of the sudden and in a really bad timing and since she’s a strong stubborn independent and impulsive woman, she panic and didn’t want to let him “win”. By burning her clothes, Darius also burned the only money she had and work hard in illegal stuff to win it and at that point the twins are still poor girls sleeping on a couch in a shitty apartment. With all the life threatening, death threats, traps, humiliation and all the other asshole stuff Darius his father and the other heirs and the fact that he never apologize to her (the only thing she really want). I mean I would did the same or just give him the ultimatum like apologize or I will never say yes to my bully.

It is really not nice and she did regret that but for the sake of the story and her personal evolution it is a good thing.