sportswoman vs adult female

sportswoman and adult female both are nouns.

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

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

Other hypernyms of sportswoman include sport, woman.

sportswoman (noun)	adult female (noun)
a female who engages in sports	an adult female person (as opposed to a man)