stepgrandniece

1- Stepsibling's granddaughter.
2- Sibling's stepgranddaughter.

My stepgrandniece is a good person.

grandparent

Parent's parent.

My grandparent is a good person.

step-co-parent-in-law

Stepchild-in-law's parent.

My step-co-parent-in-law is a good person.

stepaunt-in-law

1- Steppibling's wife.
2- Spouse's stepaunt.

My stepaunt-in-law is a good person.

step-co-mother-in-law

Stepchild-in-law's mother.

My step-co-mother-in-law is a good person.

mother-in-law

Spouse's mother.

My mother-in-law is a good person.

half-nephew-in-law

1- Half-nibling's husband.
2- Spouse's half-nephew.

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