1- Step-great-grandchild's child.
2- Great-grandchild's stepchild.
My step-great-great-grandchild is a good person.
The subsequent offspring of members of the 1960's peace-and-love movement. AKA children of the original hippies.
"Do you see that kid, River? His parents are such hippies, he's a flower grandchild."
Great-great-great-great-great-great-grandchild.
My 7X-grandchild is a good person.