Family code is a set of laws, or codes, that specifically pertain to the family, such as those that govern marriage, divorce, adoption and child welfare. When citing family code in a paper written in APA style, the rules of referencing any legal code applies and does not differ based on the type of code you are using.
The Reference Page
All of your citations are to be listed alphabetically by the first piece of information presented in the item. As most references are books or other written articles, they are listed alphabetically by last name. Since a legal code does not have an author, it will be listed by the code entry.
Here is the format: name/title of code entry, name of source. § information identifying specific code entry (generally section numbers) (publication date). Note that the publication date means publication of the document, which does not necessarily correlate with the date of the act.
An example could be listed as follows: New Jersey Family Code, New Jersey Code § 71F-1-189 (2012)
When discussing the code in your paper, simply list the name of the code followed by the publication date in parenthesis. Here is an example: New Jersey Family Code (2012).