Just think when Zuko visits babyKorra they would play hide and seek together and he would find her and shout “I’VE CAPTURED THE AVATAR” holding her up like Lion King.
Consider also:
Zuko picking up little Korra at some point during their first meeting. Sokka turns around to instantly go, “You finally captured the avatar. Congrats my man.” And Zuko, who is still working on how to treat this new little avatar, just cracks tf up.
Little Korra instantly decides she likes this firelord dude, because that laugh feels like the laugh of a friend to her.