Expecting too much from my child?

My daughter just turned 2 in November. She will not take instructions that she doesn't like. When I tell her not to climb and smiles and does it. When I tell her not to touch something she smiles and does it. She knows and thinks it's funny to do the opposite.

I've about had enough, I'm ready for running to the hills. I have a newborn here and she is going to end up hurting him if she doesn't start listening to me.

Am I expecting too much? I think she needs discipline but everyone says "she's too young, she's such a good girl". Yea she's great outside out home but when it's just us during the day she is wild.

Her temper is out of control and I can not take it anymore