The John F. Kennedy Administration-Who Were "Fiddle and Faddle"?

I was reading an account of JFK’s time as president…and the book relates seve5al incidents when Kennedy swam in the White House swimming pool. He was accompanied by two young women (secretaries?) , who the Secret Service agents dubbed “Fiddle and Faddle”. From these accounts, these women provided numerous"services" to the president…none of which will be mentioned here.
Who were these women? And, did either of them ever comment later upon the nature of their employment in the White House?

Esteemed White House correspondent Hugh Sidey claims they existed:

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