Our 4.5yr old DD started the terrible 2's at 3yrs when we moved to Canada. I have almost consistently put her in her room and held the door until she has calmed down, then told her she can come out when she decides to be good, as sometimes she's not ready to come out as she is still sulking. Sometimes she falls asleep in there so I open the door a bit so she knows she can come out when she wakens up.
The last few months DH has decided himself that it would be a good idea to take toys away from her if she doesn't answer and on occasion smacked her (i don't agree with it and have told him). He has even tried to put her on the step but that just makes her worse as she is soo stuborn that she will just keep getting off even if you were to sit there for an hour.
The past couple of weeks I have told DH that the only way of dealing with her is to put her in her room and hold the door until she calms down. I can do this but DH can't stand listening to her kick the door and wants to go in a smack her. (he hasn't done this and usually asks me to take over and hold the door). DH wants to do something else that he might be able to handle but I can't think of anything. I want to keep up with putting her in her room and this phase will pass and she will get the message.
We also have 2 DS, DS1 is 6.2yrs and DS2 is just over 8 months old. DS1 is just a typical boy with loads of energy and will go to his room for time out.
So I just don't know what to do with DD.
Sorry for the long post, hope you got to the end!