jeune fille vs young lady

jeune fille and young lady both are nouns.

Word	Noun	Adjective	Verb	Adverb
jeune fille	Yes	No	No	No
young lady	Yes	No	No	No

As nouns, young lady is a hypernym of jeune fille; that is, young lady is a word with a broader meaning than jeune fille:

Other hypernyms of jeune fille include fille, girl, miss, missy, young woman.

jeune fille (noun)	young lady (noun)
a girl or young woman who is unmarried	a young female