Sometimes this is avoided by using both the masculine and the feminine pronoun; for example,—
Not the feeblest grandame, not a mowing idiot, but uses what spark of perception and faculty is left, to chuckle and triumph in his or her opinion.—Emerson.
It is a game which has been played for untold ages, every man and woman of us being one of the two players in a game of his or her own.—Huxley.
By using the plural pronoun.
411. Another way of referring to an antecedent which is a distributive pronoun or a noun modified by a distributive adjective, is to use the plural of the pronoun following. This is not considered the best usage, the logical analysis requiring the singular pronoun in each case; but the construction is frequently found when the antecedent includes or implies both genders. The masculine does not really represent a feminine antecedent, and the expression his or her is avoided as being cumbrous.
Notice the following examples of the plural:—
Neither of the sisters were very much deceived.—Thackeray.
Every one must judge of their own feelings.—Byron.
Had the doctor been contented to take my dining tables, as anybody in their senses would have done.—Austen.
If the part deserve any comment, every considering Christian will make it themselves as they go.—Defoe.