Lady Stornaway (nee Flora Ross) is a friend of Mary Crawford and the sister of Janet Fraser, who resents her because they had nothing and Lady Stornaway married the richer man. She was in love with Henry Crawford the first winter after she came out. She jilted a nice young man in the Blues for Lord Stornaway, and Mary has cared little for her for the last three years.
Mary goes to stay with her after Easter, and when he visits her at Lady Stornaway's house, Edmund Bertram thinks Lady Stornaway and Mrs. Fraser are bad influences on Mary. Following Maria Bertram and Henry Crawford's elopement, Lady Stornaway writes Edmund a note begging him to come see Mary. When the meeting goes poorly, Edmund and Mary's understanding ends.