The pleasure of love, is a classical French love song written in 1784 by Jean-Paul-Egide Martini (17411816).
Here is an arrangement for easy piano duet 4 hands.
With downloadable mp3 for audio-help, 2:28 min

La Marseillaise was written in 1792 by Claude Joseph Rouget de Lisle in Strasbourg after the declaration of war by France against Austria, and was originally titled "Chant de guerre pour l'Armée du Rhin". The Marseillaise was a revolutionary song, an anthem to freedom, a patriotic call to mobilize all the citizens and an exhortation to fight against the tyranny and the foreign invasion. The French National Convention adopted it as the Republic's anthem in 1795.
Here is a piano duet 4 hands arrangement, 4 pages (2 pages both hands, 1 page prima, 1 page seconda) with downloadable mp3s just for audio help.

Ten short Duets 4 hands themes from romantic and classcical era for early intermediate piano.
By Mozart, Beethoven, Chopin, Adam, Halevy, Donizetti, Weber.
Includes parts for both players.
With downloadable mp3's for audio help (21 pages).
First published 1877.

Three works for piano duet 4 hands. Adolf Terschak (1832-1901) Children's dance (Mazurka, Polka) Paul Hiller (Christmas Eve).
Includes downloadable mp3, 21 pages, intermediate.

Ah! vous dirai-je, maman is a popular children's song in France, which has had numerous lyrics on different themes since its composition in the 18th century. This song was popularized in Twelve Variations on Ah vous dirai-je, Maman by Wolfgang Amadeus Mozart.
Piano duet 4-hands, 5 pages (3 pages both, 1 page prima, 1 page seconda) with downloadable mp3 for audio help.