Is your brother thin?
No, he isn't. He's big.
Who's he?
father
Who are they?
They are my parents.
Is your sister slim?
Yes, she is.
Who's she?
mother
Who's she?
sister
Who are they?
They are my grandparents.
Who's she?
aunt
Who's the chubby baby?
He's (she's) my baby brother (sister).
Who's he?
brother
Is your grandpa young?
No, he isn't. He's old.
Who's the good-looking woman?
She's my sister/aunt.
Is your cousin tall?
No, she isn't. She's short.
Who's he?
uncle
Who's he?
grandfather
Who's he?
baby brother