What the OP has written about sounds similar (ish) to what our 6yr old lad is like at the minute.
A simple stop it was sufficient, now he continues to do whatever it is, but more so. We get answered back “how are you going to stop me doing it?”. On the naughty step he now asks how long he has left, and says it doesn’t work. Sometimes he will randomly ‘play fight’ with one of us, hurting us a little, we tell him it hurt and to stop, so he does it more, we end up having to restrain him, and then walk away.
Sounds bad, but 99% of the time he is actually a great kid.
Afterwards he says he doesn’t realise he has done these things, and we actually believe him (stupidly?). We think its a stage thing. Certainly his brain is developing and he is learning that he has independence, we think this is just how it is manifesting at times. He is genuinely upset after.
All I would say to OP is do you make her aware of the consequence of her actions. ie does she know she will have to pay for damage ie no money for treats/pocket money etc.