Maréchal Le Pen became France's youngest MP at the age of 22 in 2012 but announced that she would not stand again for "personal and political reasons" after last year's presidential election.
She is more conservative than her aunt, Marine Le Pen, who is the party's current leader and won a historic 10 million votes in the second round of that election but did not perform as well as had been predicted.
In her speech to Cpac, to be held in the Gaylord National Resort & Convention Center just outside Washington, she will call for right-wingers to join hands across the ocean, according to the far-right website l'Incorrect.
Cpac is an annual event, attended by Republican politicians, right-wing media celebrities and former members of the US military.
British Europhobe Nigel Farage is to attend this year, having been warmly received last year following the Brexit vote.
Last weekend Farage gave a video address to the founding conference of the Patriots, a break-away from the FN led by its former vice-president, Florian Phlippot.
The FN is to hold its annual conference next month and Jean-Marie Le Pen, who has been expelled but, following a court ruling, remains its honorary president, has threatened to attend in defiance of his niece.