I agree with you about her, Ponders, plus Yamile Aldama, I cannot take any pride in their performances when they have already competed for other nations at top-level events. But can't you see the difference between them and Mo Farah? He came to England when he was 8, grew up to adulthood and became the world-beating runner he is in this country, and has never competed for any other nation.
Anguilla has the same status as The Falkland Islands (British Overseas Territory) - and she has had a British Passport since birth.
