Possible Clues:

• Dame Edith, Sir Osbert or Sacheverell
• Dame Edith —, poet
• Dame Edith --, English poet
• Writer who may look good on a horse
• Take exam on flourishing poet
• Poet one introduced to Eliot, initially, around spring
• English literary family perch by spring
• Exactly what's needed in excellent poet
• Prove pleasing
• Dame Edith —, English poet