I would suspect you were a little unusual.
From the pictures posted this poor girl did not look as precocious as that.
No, she didn't look well-developed from what I could see, but it's hard to tell. And FYI, average onset of menstruation is now around 11 (though it was still a couple of years later back when I was that age -- it has been dropping steadily for decades). And of course many girls beging menstruation before they are full-grown.