Etimology
From Middle English. Equivalent to her + -self.
pronoun
herself (the third person singular, feminine, personal pronoun, the reflexive form of she, masculine himself, neuter itself, gender-neutral singular themself or themselves, plural themselves)
(reflexive) Her; the female object of a verb or preposition that also appears as the subject.
(emphatic) She; an intensive repetition of the female subject, often used to indicate the exclusiveness of that person as the only satisfier of the predicate.
(Ireland) The subject or non-reflexive object of a predicate; she (used of upper-class ladies, or sarcastically, of women who imagine themselves to be more important than others)
Examples
She injured herself.
This time was most dreadful for Lilian. Thrown on her own resources and almost penniless, she maintained herself and paid the rent of a wretched room near the hospital by working as a charwoman, sempstress, anything. In a moment she had dropped to the level of a casual labourer.
She was injured herself.
What's herself up to this time?
Have you seen herself yet this morning?