You tell her that Angela best suits her because she sounds like an angel and has white, angel-like hair. Your older sister Selene seems mesmerized by the name you gave to the newbie. The newbie says "Angela, I like that name, it definitely does fit me, I have the look of an angelic zombie after all. Your mother Anne mentions that she'll need somewhere to sleep, Selene put Michelle with you after all, and it would be your turn to choose the newbie's room.
You have two options, the first option is to have Angela sleep with your older sister Selene, the second is to have her sleep with your other sister Dianna.