Possible Clues:

• Gaunt — British author, d. 1925
• How difficult it is to get around a horse that's so gaunt
• Rider's unyielding, restraining a gee-gee
• Englishman who wrote, having drawn
• No drop of her blood was human, was said by Rossetti of this wife of Adam
• Rider of hollow-eyed appearance
• She came from him looking emaciated
• A horse looks so worn in such difficult surroundings
• Looking worn and exhausted
• Rider finds it difficult to hold a horse