sister

I have only one sister.

I have only one sister.

I have two sisters.

I have two sisters.

She is two years younger than her sister.

She is two years younger than her sister.

I have two brothers and a younger sister.

I have two brothers and a younger sister.

I bought a birthday present for my sister.

I bought a birthday present for my sister.

She is very patient with her younger sister.

She is very patient with her younger sister.

My sister is pregnant with her first child.

My sister is pregnant with her first child.

She was jealous of her sister's success.

She was jealous of her sister's success.

By comparison with her sister, she is very tall.

By comparison with her sister, she is very tall.