Thanks for your messages.
I am actually looking at my 3-year-old in a different way today than I had in the past. She is a difficult child, to be sure. She was diagnosed with sensory processing disorder at 2 years old. Ever since she could walk, she would get out of the bed in the middle of the night, go and play and then come back when she was tired again. She doesn't like to communicate very much, and will always do things herself or scream rather than ask for help, though she does not have a speech delay. She gets frustrated easily and used to have severe rage problems where she would bite and scratch her brother or the dog or me! One of her doctors sent us to a child psychiatrist who wanted to drug her up with all kinds of medication and then sedatives at night, after only meeting her for 10 minutes! Of course, I refused. She is in a special needs school now and is doing very well. Her teacher says that she has good cognitive and speech, but just doesn't "engage" as much as a "normal" child would.
I have never thought there was anything wrong with her, though everyone around me kept telling me there is. Now I have a new outlook.