Bolin: Do you think your dad knows about this tunnel?
Katara loves both Aang and Korra, she gets to be with the Avatar in 2 lifetimes.
Toph learned to “see” through the use of her earthbending, feeling people and other objects through their vibrations, which she sensed through the ground via her bare feet She can also sense secret tunnels, and she taught this to her daughter.
Zuko and Korra both have great father figures, no matter how stubborn they are and how much they disregard their wise advice, both Tenzin and Iroh still care for Korra and Zuko and would always be there for them.
Parallel requested by Anon.