congresswoman vs adult female

congresswoman and adult female both are nouns.

Word	Noun	Adjective	Verb	Adverb
congresswoman	Yes	No	No	No
adult female	Yes	No	No	No

As nouns, adult female is a hypernym of congresswoman; that is, adult female is a word with a broader meaning than congresswoman:

congresswoman: a female member of the United States House of Representatives
adult female: an adult female person (as opposed to a man)

Other hypernyms of congresswoman include representative, woman.

congresswoman (noun)	adult female (noun)
a female member of the United States House of Representatives	an adult female person (as opposed to a man)