It's a common phrase used to ask about the well-being of a girl or young woman.
Here's a breakdown of the phrase:
* Como: How
* Esta: Is (present tense of estar)
* La: The
* Chica: Girl
You can also use this phrase to ask about a specific girl, for example:
* Como esta la chica que trabaja en la tienda? (How is the girl who works in the store?)