Can it bring about biological change, or simply a precocious mindedness?
Some studies have shown that physical molestation of girls or exposure to sexual material/stimuli can trigger the changes in the brain that signal the glands to produce the hormones that result in puberty.
It’s a very interesting area of endocrinology. 15 or 20 years ago, scientists believed that most of the decline in the age of menarche was traceable simply to body weight/fat levels, but more study has shown that this is only one of a wide variety of factors behind the phenomenon.