@Michelle2137
You will notice Sophia, who gave you that review is a new Airbnb guest user, and although she joined in 2016, this was her first review. It is obvious from her written public review and also her private comments to you that she does not understand the review rating system. This is also complicated by the fact that she is of Asian extraction and although living in Australia may not have a good mastery of the English language.
Get onto Airbnb in Sydney on 0285203333 and explain to CX what I have detailed here and, although they won't be able to alter the star ratings, they will be able to remove the review so it won't reflect on your stats.
Michelle, this is an obvious mistake and I am sure you can get this removed from your stats!
Cheers........Rob