OK, it doesn't work at any buffet or family style restaurant. There, you strictly pay per person, and any persons under 3 are free.
At a restaurant where you order off a menu...you can order one meal and ask for an extra plate. You can order (and pay for) an extra drink if desired.
Many of the restaurants have decreased the serving sizes of the entrees, so there may not be enough for 2 people. However, if you have a light eater (like mom who is always trying to lose weight!), it can work.
Another approach is to use a dining credit to get one full meal (appetizer, entree, and dessert), and pay for a second entree. You then share the appetizer and dessert.
Disney (and the dining plan) don't care who actually eats the food. You get the food you are allowed on the plan...and if you are doing a "split", you pay for any extras you might want. The servers have no problem with this. Just remember to tip them on any out of pocket items. If you order anything out of pocket (even just a coke), you will receive 2 bills--one will show the dining credits used and remaining, the other will list the cash items. You can then pay for those with cash, charge to room, credit card at restaurant, or whatever. Just let the server know what you are doing when you order if some items are to be out of pocket.
I don't know if 2 adults, a teen, and an 11 year old would have enough food with 2 meals. It might work at the steak places where you know exactly how much meat you are getting. If your teen is a "growing boy," there is no hope! However, 4 of you might share 3 meals...... Or 4 of you might share 2 meals and just purchase one or 2 additional entrees.
I'm not sure what your goal is--saving TS credits for signature restaurants or using 2 TS per person in one day? Or something else?
Most people find that they have plenty of food on the plan.
