The Duchess who warned the world about Hitler and Stalin

Actual title: Katharine Stewart-Murray, Duchess of Atholl

Excerpt:

she resigned ....again in 1938 in opposition to Neville Chamberlain's policy of appeasement of Adolf Hitler and to the Anglo-Italian agreement.

I'm not really finding support for the title used here. (The Duchess who warned the world about Hitler and Stalin) The above seems to be as close as it gets.