G.♣.
The only thing normal about periods during those early teen years is that there is no such thing as normal or regular periods for most teens. It can take a couple of years before there is anything predictable, and for some of us lucky ones (please read much sarcasm here), our periods are never normal or regular.
If she were my daughter, I'd probably call the doctor, too, just to be safe. But my honest guess would be that there's nothing wrong. It just is what it is.