Who ranks higher duchess of Cornwall or the princess royal?

The only female with in the British Order of Precedence ranked higher than the Duchess of Cornwall, at this time, is Her Majesty the Queen. If Her Majestys mother had still been alive, she would have ranked between the Duchess and Her Majesty.

In the case of Anne, the Princess Royal, being a daughter of the Queen, she is ranked below the wives of the younger sons of the Queen, thus placing her fourth, under Sophie, Countess of Wessex, and, until their divorce, would have been placed under Sarah, Duchess of York, wife of Prince Andrew.