Ok I'm 37 yrs old and I can tell you she can have panic attacks that early. I had them that young but wasn't diagnosed until the age of 18. Please go and get her diagnosed now, it will save her so much emotional pain.
Perhaps you have done this already but, if not, be sure to have her evaluated medically. Why? Because panic attacks, again in the strict sense of the term, involve the activity of the autonomic nervous system and this aspect of the central nervous syetm can be influenced by a variety of medical conditions.
I have no idea. They just happen at random times and places. I have been keeping a journal of what times, activities, etc. Not seeing a pattern.
It is unusual for a child so young to have panic attacks in the strict sense of the word. What prompts these episodes?