stephencottontail on "navigation wrapping to second line"

If there aren't any plugins being used, someone must have made some pretty heavy adjustments to the Twenty Twelve theme, because the default version of that theme doesn't have near that many customizing options. Can you post your functions.php from the parent theme to Pastebin and post the link here? Also, in this case you might consider trying to contact whomever worked on the website before you.