After the death of her first husband and her second marriage she lost Hatfield but continued her strong presence in British politics.

She was rumoured to have leaked confidential information to the Russian Ambassador Count Shuvalov, though the certainty of this is unclear.

[6] However, Disraeli nonetheless used the idea to alienate Lord Derby amongst the cabinet colleagues, in an effort to gather support for a firmer approach against Russia in the Russo-Turkish War (1877–1878).

[7] Jennifer Davey regards Lady Derby's political involvement in the Eastern Crisis to have almost destroyed her husband's career, who resigned twice as Foreign Secretary between January and March 1878 before defecting to the Liberal Party.

[8] Lady Derby was also in regular correspondence with her friends who included Charles Darwin, the Duke of Wellington and Sir Henry Irving.