I absolutely love this! It's adorable and I think it's wonderful that that's how he got his human name, and her being just as excited as him is so sweet!
I caught a typo or two, I hope you don't mind if I point them out...
"their own very young son was *one* already one of the most notorious troublemakers"
and "Our people know it as Sol *iii*."
I really hope you continue this! I was trying to find the previous parts since this is listed as part 4, which tag is this story under?

Oh, and this is definitely going in my headcanon too. You somehow have a knack for writing stories that by their sheer brilliance end up there ;)