[From the sky? An airbender? How could that possibly be?]

You would be an Airbender then?

[Although in the grand scheme of things, if this was a different world, anything was possible]

Grandpa and Katara? I am familiar with the name. She is an excellent water bender, who wears a water tribe engagement necklace?

[Logic dictated only Aang could be the grandfather, but he was only nearing the age to think about a family, not have one with kids of their own]