Your kids will probably like the character buffet dinners best anyhow! And those are "free" for under 3. Normally they aren't the best deal on the dining plans as other places cost more, but since you are feeding triplets......
You might have enough food to feed the triplets off your plates at a normal restaurant--they don't eat much, and you will have 2 adult meals with appetizers and desserts. It really is a lot of food.
At CS, you can order a double hamburger and pay 90 cents for an extra bun. I'll bet your 2 year olds won't eat more than 1/2 of a burger anyhow. (they are 1/4 pound patties, so a double has 1/2 pound of meat). Before the dining plan we always took a box of the favorite cereal along--you can buy 1/2 gallon of milk or juice at your resort and have a cheap breakfast. That way, you can save your CS credits for lunch and use TS for dinner. If the kids have favorite snacks (rice krispie bars, fruit roll-ups, or whatever) you can throw a couple boxes of those in the suitcase also. Since you will have 3 snack credits per night, these might save you $$ in the parks. You can also take juice boxes to the parks--any place that serves coke on ice will give you a free cup of ice. Also, since you will have beverages with the CS meals....you can order extra cups of ice and split the drinks.
To decide on the value.....a character dinner is $27.99 plus 6.5% tax plus tip. That puts you at about $34-35 for the meal for an adult. They are about $10 for a child 3-9. So, no brainer, it is a great deal for your 4 year old. Her CS and snack are "free." For the adults, your CS meal just cost you $3-4 instead of the $12-15 it would have cost. Remember, at lunch with CS you will have a dessert and beverage included. You would have paid about $8-9 for a burger/chicken sandwich, whaterer, $2 for beverage, $4-5 for dessert! In addition, you have a snack credit. It's a good deal without free food for your triplets.