Who's this?
Dad
Who's this?
baby sister
Who's this?
uncle
Who's this?
Grandma
Who's this?
aunt
Who's this?
Grandpa
aunt / cat
This is my aunt's cat
Dad / car
This is my dad's car
Who's this?
cousin
Who's this?
Brother
Who's this?
Mum
Who's this?
Sister
grandma / umbrella
This is my grandma's umbrella
sister / book
This is my sister's book.