And the correct answer was ...

Props to Baywatch for going out on a limb, risking everything, and posting a comment. Very close, there, B. But the correct answer is Tennessee.

When we came back from our whirlwind Smoky Mountain/Atlanta trip, N asked Boo what her favorite part of the trip was. She said swimming in the hot tub. There was a pause and I asked Nea what her favorite part was. She said "Up yellow. Up yellow chair." I used my SuperMommy powers and deduced the following.