Since you are an international traveler you will have to clear customs/immigration first. After you claim your baggage unless you are continuing on your journey that day you must leave the terminal. There is only one exit for customs in Terminal A.
If your family is in transit to another country they will be escorted to a transit lounge right after they deplane. If this is the case you will not be able to visit with them. If they are headed to a stop in the US you might see them in Customs.
Be aware that there is not anything to do except smoke outside of DFW
airport terminals. There is a hotel at the airport but you will need to take a Taxi to the hotel and one back to the terminal.
Good luck and enjoy your visit.
"Any airline that wants to serve the [region] can go to DFW today and fly anywhere they want," WN spokesman Ed Stewart