We are finding dd2 difficult to discipline as she really doesn't give a toss about any of the sanctions we impose. She is only 5, and the youngest of 3, so we are prepared for a certain amount of attention seeking but she also has to realise that there are consequences to deliberately scribbling all over her elder sister's drawings, or constantly jumping on the sofa, or spitting or scratching, or not doing what she's told etc. We've tried star charts, time out, and withholding things but she doesn't care about getting treats or having her favourite sleeping bag taken away. In fact, when she's put in time out she starts singing as if she's having the time of her life!
What do you do when you run out of options?