I have stayed in all sections of SSR, they each one have their pros but I found very little cons!
Springs: Closest to main pool and restaurants, so very convenient although it is the last stop on the bus route and the busses can be very crowded by the time they reach the Springs.
Grandstand: First on bus route, still very close to the main area and it has a nice feature pool with spray cannons and its own pool bar and drink refill.
Paddock: Probably my favorite section, stop #3 on the bus route, not a far walk across the bridge to the main area and we had lovely views. I do agree with a pp though that with the new pool being built that might make that section less peaceful (new pool is not set to open until after your visit).
Carousel: Very peaceful, #2 on the bus route about ten minute walk to the main area. One nice thing about this section is that if you have a car, its right near the entrance so nice and convenient when you are driving in and out of the resort. Once the new pool at the Paddock opens this section will be way more popular. For now with no pool of its own, and being the furthest away from the main area many do not care for it, but we enjoyed it.
Congress Park: Obviously close to DTD, lovely quiet pool with incredible views of the river and DTD, not too far from the main area. It is #4 on the bus route. Our experience was the busses were seldom full to standing room only when they stopped at Congress Park. This and Paddock are our two favorite sections.
With a 7 year old I would request Congress Park, Granstand or Springs in that order.
One thing to bear in mind is that each section has a few buildings. So even if you get Congress Park, you may be in a buidling that is a bit further to DTD but thereby closer to the Springs.
We did not find SSR too big at all. Its well laid out, its a lovely resort and with multiple bus stops and pools, no building is far to a pool or bus stop. Unlike Pop with one stop that some buildings are a bit far from. I stayed at SSR with my parents and dh's. All of whom were elderly with various health woes and they all did great walking around SSR and loved it. My kids loved it too, I think it has one of the best main pools on property and one of the best cs places for a deluxe. Not a food court but still a nice and more varied selection than most other DVC's.
Enjoy your stay!