Violet Shephard told the man that if he did not send her £3,000 to £4,000 for her and her teenage daughter to go away she would "take him to court and get his name in the papers".
Shephard, originally from Sierra Leone, told the pensioner - who cannot be named for legal reasons - she could make the entirely baseless sex abuse allegations "go away" if he handed over the money to fund an exotic trip.
But instead he went to police and reported her attempted extortion.
Shephard, 49, of Balmoral Gardens, Dundee, pleaded guilty at Dundee Sheriff Court on indictment to a charge of attempted extortion.
She further admitted breaching bail by contacting the man on a later occasion.
Fiscal depute Nicola Gillespie, said: "Family protection officers were never made aware of any inappoproate behaviour towards the girl."
Doug McConnell, defending, said he would reserve his plea in mitigation until a later sentencing date.
Sheriff Tom Hughes deferred sentence for social work background reports.