Translation:Kaʻiulani is the lazy sister of Kimo and Billy.
Okay I'm seeing, since i got it wrong again, that the question here is "A lazy sister" vs. "THE lazy sister." Since the Hawaiian "ke" can be either, in English, how do we keep from guessing it wrong? There must be some kind of indication that I'm missing! E kokua mai ke 'olu'olu.
These are 2 different and very common sentence patterns: 'aike 'O and 'aike He. One starts with 'O and the other He. See the explanation here: http://papaolelo.weebly.com/uploads/1/0/2/2/102246944/pepeke%CA%BBaike.pdf
I think because you have the answer in the possessive form. The prompt does not have "ko Kimo" which would translate as "Kimo's..." . I can't figure out how you would properly do a dual possessive (for "Kimo and Billy"). But anyway, this prompt does not have the possessive form, and I think they want us to learn the difference, so in this case, although the meaning is equivalent, the structure for expressing it needs to reflect the lack of the " 's" form.