Ok, so just debriefing the character of Alice in the first book.
Alice makes her first appearance at Forks High School. When Edward first states his attraction towards Bella, Alice is interested since she had a vision about her and Bella becoming good Friends and knew that it could one Tag happen. She is desperate to meet Bella but Edward forbids her from talking to her. Eventually, Alice takes up the courage to introduce herself to Bella.
When Bella comes to visit the Cullens' house, Alice is polite and friendly, Schauspielen as if Bella is already a member of the family.