What's In a Name?

This photo was taken just a couple of weeks ago. It is the first one we've had taken with all five of our kids.

We've had to invent new titles for the people in our family.
---
Hilary, the oldest of our children, is technically my step daughter--I married her mother when she was 18 months old. So, she was always my daughter rather than "step-daughter," even after her mother and I changed our relationship. When Giancarlo came into the picture, Hilary became his daughter, too. So she's kind of Giancarlo's step-daughter squared. And Giancarlo could be Hilary's step-father, twice removed.
.
Amelia is Elijah's aunt. But now that her mother is taking over the job of mommy for Elijah, Amelia is now the aunster, and Elijah is her brophew.
.
Rennen is my ex-wife's daughter, and my daughter's sister. I once introduced her as my niece, for lack of a better term. She later asked, "Why did you say I was your niece? I'm really more like your daughter." There is not a name in the English language for what you would call your ex-wife's daughter with whom you have a very warm and loving uncle-ish, parent-ish relationship. So? Rennen is my nieceter. And I'm her duncle, her funcle, or her uncther.
.
Which brings me to a similar quandry. Rennen is my ex-wife's daughter, and as I've established, she's my nieceter. Diego is my son, and my same-sex life partner (now husband) and I adopted him. So what does that make Rennen and Diego in relation to each other? Cousins? Siblings? Sibsins? Couslings?
.
Diego is Elijah's uncle. But again, since Claire has taken over the mommy job for Elijah, that makes Diego Elijah's bruncle. And that makes Elijah Diego's brophew.
.
Elijah is my grandson. He always will be. But since roles have shifted in our family, does that kind of make me an uncle to him in a way? So am I his granduncle? His gruncle? Or his unclepa? And is he my grandphew, or my nephson?
---
Ahhh, well. It's all just words. It's not the title that matters.
It's the relationship.
-