Nurture kinship is a way of talking about people who aren't related to you by blood, but are still part of your family. Imagine you went to a new school, and you didn't know anyone there. But then you meet a really nice teacher who takes care of you like a parent, and some students who become your best friends. Even if you don't have the same last name or genes as them, they still become your family because they love and support you.
Some people also have foster families or adoptive families, which means they have parents and siblings who didn't give birth to them, but took them in and gave them a home. This is another kind of nurture kinship, because even though they aren't related by blood, they still have a special bond that's like being part of a family.
So remember, nurture kinship means having people in your life who aren't related to you by blood, but are still family because they care for you and share a special bond.