No, we're not talking about H. Rider Haggard's novel She but that third person, singular, feminine gender pronoun in English, she. It appears that before the year 1100, there really wasn't a she in the language. English had heo, which singular females had to share with plurals of all genders because it meant they as well.

In Old English (before 1100 AD) the pronoun system was as follows, with nary a she in the bunch. (Note: I don't know how to get a macron ( = bar over the vowels] as customary in Old English, so I've substituted ë and ï to indicate the long vowels.)
Singular            Feminine            Masculine          Neuter

Nominative          hëo                 hë                 hit
Genitive            hiere               his                his
Dative              hiere               him                him
Accusative          hïe                 hine               hit


Nominative          hïe                       same for
Genitive            hiere                   all genders
Dative              him
Accusative          hïe
In the twelfth century, however, the she appeared, and she has been with us ever since. She may come from the Old English feminine demonstrative pronoun seo or sio, or from Viking invasions.

The OED explains it this way:
The phonetic development of various dialects had in the twelfth and thirteenth centuries rendered the pronouns he (masc.) and heo (fem.) almost or wholly indistinguishable in pronunciation. There was therefore, where these dialects were spoken, a strong motive for using the unambiguous feminine demonstrative instead of the feminine personal pronoun. Further, the districts in which she or sho first appears in the place of heo are marked by the abundance of Scandinavian elements in the dialect and place-names; and in Old Norse the demonstrative pronoun (of all genders) is often used as a personal pronoun.