If twos are terrible, what's four?

I know kids go through the phase nick named "the terrible twos".  I seem to have a little one who doesn't want to come out of it.  Iris is now 4.5 years. When is the cut off?  Emily never went through "the terrible twos", and Annie just had a short stint of them.  Iris seems to be an overachiever. lol  Today she had temper tantrum over not getting to ride along to take the girls to school.  Honestly I was to tired to have her tag along.  Then there was the tantrum when she wanted Annie's toy and Annie didn't want to let her play with it. The screaming over the ball almost made me lose my top.  Iris felt the need to scold me at softball because  we didn't go to Burger King for lunch.  We went to Burgerville instead and she still got a cheese burger. When I don't cave she either starts asking over and over, or starts crying which turns to screaming.  Either way we all lose.  She still needs naps but of course doesn't want to take them.  When we make her lay down in her bed she cries, screams and then a high pitched shrieking. The shrieking might break glass one of these days.  I am consistent with this kid but she seems to think I am gonna cave every time.  Sorry, Not trying to raise a spoiled brat.  I know she will grow out of this phase but it can't come quick enough.  Just like she will be completely potty trained one day and stop having accidents.  Again can't come quick enough.   I just need to see past this grey sky.