Hi Yorkiegirl, sorry that you are having such a hard time with dd2. I think all toddlers go through what you describe at some stage, but ... I find that with my dd, it does get worse just before bedtime/naptime when she is tired or when she is hungry. If your dd's early mornings are getting her down, is it possible to structure a daytime nap for her - if I see dd disintegrating but not winding down, then I take her for a walk outside in her buggy. Even if she does not sleep, a little quiet time helps to soothe jangled nerves (yours too ). After a few days of early mornings, will your dd2 have a catch up day where she seems to sleep forever? dd went through 1-2 weeks of early wakings but that later sorted itself out spontaneously.
I find that around 2 years old, sleep patterns can get a bit disrupted in that the little ones occasionally start to drop naps before they are ready with consequent disruption in their nighttime sleep and wakings. Also, speech coming in tends to affect nighttime sleep as well.
My dh does sometimes get frustrated with dd as well (I do too). So when it looks like one of us is going to blow our stack, the other will arrange a lie-in or take dd out of the house. It is trench warfare for the time being - you are doing great with more than one .
I also try not to think of such behaviour as deliberate naughtiness (often failing miserably, of course). DD2 is just testing the boundaries, as any intelligent and spunky child would. It is a crucial part of her development. Just knowing that you disapprove of the behaviour will eventually bring her round - emphasis on eventually. Maybe I am a bit of a soft touch, but with my strong-willed dd, I find less is more on the punishment front. And she does "get it" after a few weeks of telling her she is being naughty and repeatedly but unexcitedly restraining the bad behaviour.