She is an eight-year-old girl.=
The girl is eight years old.=
She is at the age of eight.
She is 8 years old.=
She is an eight-year-old girl.=
She is at the age of eight.
She is an eight-year-old girl.=
The girl is eight years old.=
She is at the age of eight.
She is 8 years old.=
She is an eight-year-old girl.=
She is at the age of eight.