First, she lived in Forks, Washington, and then her mom and her dad got divorced and she moved to Phoenix, Arizona when she was just a few months old (Twilight page 3). Then when her mom got remarried, Bella went back to Forks, WA to live with her dad (Twilight page 4). :)
first bella lived in forks then her parents got a divorce then she déplacer to AZ with her mom, then her mom got remmaried and is temporarily in FL, while bella is in forks WA with her dad (charlie).