My sister’s daughter is my niece, I know that much. Are my niece’s children my cousins? If so, are they first, third, close, kissing or what? Is my niece’s husband a relative of mine? Is my niece related to my wife? What is the relationship to my wife, if any? How about my niece’s kids? Are they related to my wife? Is there a website that clearly and lucidly explains all this kind of stuff? I never got the Southern family explanation of all this and wouldn’t care now, except that Marcie asked me and I don’t know the answer.
As always, thanks for any information that may be provided.
Each relationship in which the parties are not the same number of generations from the common ancestor are indicated by “(generations) removed” except that that sibling relationship in the first generation messes it up.
So you and your sibling are one generation from your parent(s).
Your niece is one more generation away from your parent(s).
Her children are two generations away from the common ancestor, making you a great-uncle.
Your niece’s husband is an in-law (although American usage either provides no name or calls him “nephew” or, more rarely, “nephew-in-law”).
Similarly, American usage makes your wife your niece’s aunt, although it is really an “in-law” situation.
Now, your children and your niece are first cousins (since they are the same number of generations (2) away from the common ancestor(s), your parent(s).
The children of your niece are one generation further removed from the common ancestor(s), so your children and your niece’s children are first cousins, once removed.
Your grandchildren and your niece’s children are the same number (3) of generations from the common ancestor(s), so they are second cousins, while your children and your niece’s grandchildren will be first cousins, twice removed (since your children are two generations from the common ancestor(s), but the niece’s grandchildren will be four generations from the common ancestor(s).
You might search GQ for “cousin” as this topic has come up, periodically, and someone may have found a clear way to explain it.
Your niece’s children are your grandnieces and grandnephews. Your niece’s husband is not a blood relative of yours, obviously. He is a relative by marriage.