Grey’s Anatomy fans met Maggie in the Season 10 finale, and she was introduced to us as Cristina Yang’s replacement as the Head of Cardio. However, Maggie quickly revealed she was the lovechild of Meredith’s mother, Ellis Grey (Kate Burton), and Dr. Richard Webber (James Pickens, Jr.). Before Ellis died of Alzheimer's, she put Maggie up for adoption without telling Meredith or Richard.
Although Meredith didn’t take to Maggie initially (she’s had a strange history with sisters), they eventually built a beautiful bond over the last nine seasons. Additionally, Maggie found love in Season 16 with Dr. Winston Ndugu (Anthony Hill).
Winston and Maggie married in Season 17, but their marriage has been rocky since Winston began working under his wife at Grey Sloan.
In Season 19, things between them worsened when Winston offered to give up being a cardio surgeon for their marriage, a move Maggie couldn’t respect. Later in the season, Maggie faced a decision that affected her and Winston’s marriage and careers.