Zoey's Grandma was in a car wreck, the raven Mocker caused her accident. Zoey told Aphrodite about the Raven Mocker watching after them and listening to Grandma and her conversation during the night. The Raven knew exactly were Grandma was heading and so it followed her and almost killed. Both Zoey and Aphrodite were worried and scared for Grandma. Zoey remember that she had promised her Grandma that nothing and no one will get in her way to stop the evil invading the House of Night and Neferet. Zoey had to ask Aphrodite to tell the others, Zoey didn't know what she will do if she lost her Grandma.
Its hard to lose someone you really care about. Especially if that person was like a mother to you. Zoey's mother changed after she remarried and so she wasn't a great mother. Grandma was a better mother to Zoey, she was the only one who understood her and cared about her. Its not only scary and creepy to have ravens following and listening to you but now they want to kill you and the people you care about the most. Zoey must be scared to death right now.