In the old texts picayune is used in the sense of a coin worth five cents (a nickel in modern American money) (Valdman et al. 1998: 364). It is not attested in modern-day Creole. According to the Petit Robert this word derives from French picaillon 'petite pièce de monnaie en cuivre' (small copper coin), and probably is not related to pequeninho.
Source: Neumann-Holzschuh (eds.) 1987: 102