Lorenzo's sister

Olivia, Lorenzo's half-sister in this book, looks interesting character like Lorenzo. She has the same name as one of my classmates too. I think she is a strong-minded(?) and man-like(?) person. (I don't know there is specific word that can explain it.) She calls Lorenzo first without contacting him for several years which requires pretty much courage to do because they are not actual brother and sister but half-related. In addition, she comes into Lorenzo's place by unlocking the door all by herself. She, and then, asks for help, which sounds more like compelling and does swear. I can say she is pretty funny and impish because when she tries to convince Lorenzo to make him let her in, she is being childish and screaming loudly so that the whole apartment can listen.