petite sœur

listen to the pronunciation of petite sœur
Французский Язык - Английский Язык
little sister

My little sister sure knows how to push my buttons. - Ma petite sœur sait très bien comment m'énerver.

He deprived my little sister of all her toys. - Il priva ma petite sœur de tous ses jouets.

A sibling's younger sister (used especially by children or by parents in speaking to their children)
a younger sister