stepgrandniece

1. The granddaughter of one's stepsibling.
2. The stepgranddaughter of one's sibling.

My stepgrandniece is a good person.

co-cousin-uncle-in-law

The son-in-law of one's grandparent-in-law's sibling.

My co-cousin-uncle-in-law is a good person.

step-great-niece

1. The granddaughter of one's stepsibling.
2. The stepgranddaughter of one's sibling.

My step-great-niece is a good person.

half-nephew-in-law

1. The son-in-law of one's half-sibling.
2. The son of one's spouse's half-sibling.

My half-nephew-in-law is a good person.

nephew-in-law

1. The son-in-law of one's sibling.
2. The son of one's spouse's sibling.

My nephew-in-law is a good person.

co-grandaunt-in-law

The wife of one's grandparent-in-law's brother.

My co-grandaunt-in-law is a good person.

cousin-in-law

1. The child-in-law of one's parent's sibling.
2. The child of one's parent-in-law's sibling.

My cousin-in-law is a good person.