Basing my math on these posts and having read your trip report, thus knowing you have 1 child and about her age. And you just said your largest meal is breakfast.
So, for the dining plan, standard 1 QS, 1 TS, 1 Snack. I'm assuming 7 nights, since I think you went for about a week last year.
We have:
60.64/adult = 121.28
19.23 for your daughter = 140.51/ night for a total of 983.57.
I'm not going to include tip in either analysis, since it's a factor either way.
Here's what I see for your meals if you paid OOP:
Akershus
Chef Mickey
Crystal Palace
Tusker House
O'Hana
I think you've been to most of these, and I know you said you prefer breakfast. So that's what I used in my analysis.
Akershus:
Average price is $43.66 * 2 = 87.31 + 26.09 (avg child) = $113.40
Chef Mickey:
$35 * 2= $70 + 19 = $89
Crystal Palace:
$26.87 * 2 = 53.74 + 14.98 = $68.72
Tusker House:
$31.5 * 2 = $63 + 17 = $80
O'Hana (I went with dinner here, since you didn't mention it as a character):
$39.4 * 2 = $78.8 + $19.17 = $97.97
Total For TS: $449.09 (without tip).
Money left to meet dining plan = $534.48
Okay now let's add snacks and late lunch dinner.
Let's say you get three Mickey bars (one per person), every day, for the 7 days:
$4 * 3 = $12 / day * 7 = $84 on snacks.
Now let's say you all go to your average priced QS, Cosmic Ray's, everyday for 7 meals. You each get an entree, dessert, and a beverage.
Entree ~$10, Dessert $4, Beverage $3 = $17/adult = $34.
Kid's Meal = $6
Total = $40* 7 = $280
Now for 7 nights, I've only got 5 sit down meals, so I'll add two more quick service since you'll likely eat two meals on those days, or another $80.
Our total is:
TS: $449.09
CS: $360
Snacks: $84
Total: $893.09
So our dining plan was $983.57 with 7 table service meals, 7 QS, and 7 snacks.
The difference is $90.48.
In other words, the difference is about the cost (before tax) of a meal at Chef Mickey. So, if you were to add just one more meal at a sit down restaurant to your plan, you would come out ahead. And that's without any other snacks, "Mom, I'm thirsties," etc.
It's all up to you, but I thought laying this out would help. This does make some assumptions on what you and yours eat, for example if you never got a CS dessert you would save $80 right there and that would make it break-even for two more table service - essentially the same OOP for the number of meals.