Dear ANON, In my opinion , and my only experience is raising 2 stubborn rambunctious boys, if you have employed the stated techniques repeatedly she might need to be evaluated ? How verbal is she ? Is she acting out because she is having a hard time communicating her needs and wants ? Even if a child is only slightly behind in speech skills it can cause all kinds of behavior issues. Try to get a referral to a large teaching hospital for the testing if possible, they will be up on the most current research in the area.
If you have been using a different technique every time then pick one and stick with it 2-3 weeks at least for it to sink in , I think the amount of time a 2 year old can handle time out is about 60 seconds but I am not positive on that fact. Make sure your expectations arent too high, Limit her choices throughout the day, be consistent, be calm and loving.
Last thought, when I went to visit my son's 3 year old classroom one day I noticed that when the teacher wanted the kids to be quiet she would whisper. The children had to quiet down to hear her. It worked like a charm.