first co-cousin-nibling-in-law 

The grandchild-in-law of one's parent-in-law's sibling.

My first co-cousin-nibling-in-law is a good person.

first co-cousin-nibling-in-law by Elivaldeq November 24, 2019

first step-cousin-nibling 

1. The grandchild of one's parent's stepsibling.
2. The stepgrandchild of one's parent's sibling.
3. The grandchild of one's stepparent's sibling.

My first step-cousin-nibling is a good person.

first step-cousin-nibling by Elivaldeq November 24, 2019