<p>This might sound stupid but just listen. In ATLA Iroh was the only known REGULAR human that could see into the spirit world, when he got captured In the Winter Soltice Part 1 he saw Aang riding Fang and the earthbenders that captured him never did. Also Zhao said he had heard of Iroh's journey into the spirit world. So Iroh was the only REGULAR human we know of that could see spirits and enter the spirit world and what can Jinora do? The exact same. She saw the dragonfly bunny spirits when nobody else could and SHE led Korra into the spirit world. Something not even her HIGHLY spiritual father could do. Connection? Now before you say "thats impossible we saw Iroh in Book 2 of Korra." Correction. We saw his spirit. He had left his physical body behind in the material world. Plus, we saw the past Avatar spirits talk to Aang in the spirit world all the time. Does that mean him and all the other Avatars weren't the same person. No. I think Iroh had two spirits inside him. His own spirit and another spirit(quite like Raava or Vaatu but not the same) that gets reincarnated. This is just a theory. Feel free to agree or disagree. </p>