"maybe next time, you'll hurt like I do." SIENNA SPIRO isabella grey, 'big grey', is meredith grey's older sister. she has had a successful career in Mayo Clinic, so her move to Seattle Grace was questionable. the successful pediatric surgeon left her family as soon a she turned 18, opting to stay at her friends house, mark sloan. meredith hated her for leaving her alone with their emotionally unstable, but awesome surgeon of a mom. what happens when isabella moves from Mayo to Seattle Grace? ocxoc