No no no! That cannot be a correct translation. The English phrasing is redundant. What about "He wahine ʻeleu kona kaikuahine"? - "An energetic woman, his sister!" would at least be a more common phrase. So many of the sentences in this lesson set are confusing because the English sentences assigned to them make little sense.
I suppose rewriting the prompt in English could have been "His sister is an energetic one," but I am not sure if there is an adequate Hawaiian translation for that.
. Sibling. Kaikuaʻana, kaikuʻana (older of a female); kaikaina (younger of a female); kaikuahine (of a male);