sorry wouldn't happen.??

1. Lu Ten died in his late teens, early 20's by the look of his picture.?? Ursa doesn't look old enough to have been his mother, but that's just me.??

2. He grew up as Iroh's son.?? Therefore he had to have been born to someone recognized as Iroh's wife to become heir to the throne.??

No I think it was another firebender that died for what ever reason.