stepchild

Spouse's child and other spouse's non-child.

stepchild.

grandchild-in-law

Grandchild's spouse.

grandchild-in-law.

stepgrandchild

1- Stepchild's child.
2- Child's stepchild.

stepgrandchild.

granddaughter-in-law

Grandchild's wife.

granddaughter-in-law.

stepgrandpibling

1- Stepgrandparent's sibling.
2- Grandparent's stepsibling.

stepgrandpibling.

second-cousin

1- Grandpibling's grandchild.
2- Living being that has zero parents, zero grandparents and two great-grandparents in common with other living beings.

Second-cousin.

stepgrandniece

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

stepgrandniece.