A family member in the country ain't crude (5-5)

'a family member' is the definition.
The definition and answer can be both people as well as being singular nouns.
Maybe you can see a link between them that I can't see?

'in the country ain't crude' is the wordplay.
'in the' means one lot of letters goes inside another.
'country' becomes 'Greece' (Greece is a European country).
'crude' indicates anagramming the letters.
'aint' anagrammed gives 'atni'.
'greece' going around 'atni' is 'GREAT-NIECE'.

Can you help me to learn more?