petite sœur

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

How's your little sister? - Comment va ta petite sœur ?

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