Question: I've been taught that a *child* is gender-neutral noun. But in the textbook on linguistics I've been reading, the noun is used as feminine. For example, a sentence in the book goes like this:

> 
> The child must also learn many aspects of grammar from her specific linguistic environment.
> 
> 
> 

Is there an explanation for the use of the pronoun *her* instead of *its*?

Answer: 
The word *child* is indeed gender-neutral. In fact, really English as a whole doesn't have grammatical gender. All that matters is the gender of the actual person that it is referring to.

If the child being referred to is a boy, then you use *he*. If the child is a girl, you use *she*.

If the writer is not really referring to a specific child (as in this example), then you have a problem. Traditionally, writers used the male *he*. In modern English, that implies that all children are male unless otherwise specified, which smacks of sexism. Some use the wordy *he or she*. Others use just *she*, as a sort of corrective to centuries of assuming maleness. Still others borrow *they* to refer to a single generic person.

Of course, it's also possible to rewrite the sentence in the plural.
From historic perspective, `it` used to be an appropriate pronoun for a child.

<http://archive.boston.com/bostonglobe/ideas/articles/2008/09/28/a_girl_called_it/>

This is similar to other Germanic languages that have grammatical gender (which has degenerated in English except rare cases like ship-she), like German "das Kind" or Dutch "het kind".

Modern connotation of the neutral pronoun in American English seems to have changed as other responses note.