EXCLUSIVE: Grey Sloan Memorial will be losing both of Ellis Grey’s daughters this season. Kelly McCreary, who has played Maggie Pierce, Meredith Grey’s (Ellen Pompeo) half-sister and head of the hospital’s cardiothoracic surgery since the end of Season 10, is departing ABC’s Grey’s Anatomy after nine years. Her last episode as a series regular will air April 13. Like Pompeo, who is set to return for the Season 19 finale after Meredith’s big Feb. 23 sendoff, Maggie also will pop in to visit the doctors of Grey Sloan later this season, following her April 13 farewell.