She is known for her brief sexual relationship with the 19-year old Albert Edward, Prince of Wales (Bertie), prior to his marriage to Princess Alexandra of Denmark.
She met him at a party in England and again when the Prince was spending 10 weeks at Curragh Camp in Ireland with the Grenadier Guards in the late summer of 1861.
Guards officers later brought her to Ireland from England for the same purpose, and coded notes in the Prince's appointment book refer to trysts with "NC" on 6, 9, and 11 September 1861.
[11] The Prince of Wales's affair with Clifden resumed after his return to London, which gave rise to gossip and scandal, but did not last long.
[12] He wrote to Carrington from Constantinople, while on an official tour in spring 1862: "I am sorry to see by your letter that you still keep up an acquaintance with NC [Nelly Clifden], as I had hoped that by this time that that was over".