Victoria is seeking revenge against Bella after the loss of her lover. She never expected Bella to welcome her presence, asking for help in seeking revenge against Edward for breaking Bella's heart.
Bella has an older sister and younger brother, she hasn't seen her sister in nearly 3 years and only seen her brother a couple of times. It's her wedding day and her mum is bringing them both. Bella has a hatred for her sister that grows when she sees her for the first time again at her wedding. The Cullen family see bella's true colours and are not happy with the way Bella acts with her sister.