If you don't want to stay in the airport until morning, you can continue traveling through the night. The linchpin of this plan is Amtrak Train 65, which departs New York Penn Station at 3 AM and arrives at Philadelphia 30th Street Station at 4:35 AM. Schedule here. The "transit" option of Google Maps shows an itinerary that goes as follows:
- Airtrain from JFK to Jamaica Station, departing around 1:15 AM;
- Long Island Railroad from Jamaica to Penn Station;
- The aforementioned Amtrak train to Philadelphia;
- A combination of SEPTA trolleys and NJ transit buses to get you to Marlton (including a 1-hour bus ride starting at 5 AM);
- and, to cap it off, a two-mile walk to your actual destination.
If you were adventurous/insane enough to attempt this, I would just catch a cab at 30th St. Station to Marlton. It'll still run you into money, though; you're looking at $54 for the Amtrak ticket (as of this writing) and probably a $50 cab ride as well, plus whatever fares are needed for the AirTrain and the LIRR.