In the singular, the definite article can only occur with the demonstrative when the noun is feminine. It is however not obligatory. In the plural, preposed le is obligatory when the noun is animate.
Note that in the Old lect (represented by 19th-century texts), we analyze preposed la as a definite article when the noun it precedes is also followed by a demonstrative determiner. In the default lect, however, preposed la is analyzed as a definite article when the noun is followed by a demonstrative determiner. The difference in analysis is due to the fact that agglutination is more pervasive in 19th-century texts and preposed singular definite articles are virtually absent, whereas (presumably through decreolization), preposed definite articles are common in modern-day Louisiana Creole.
Source: Neumann 1985: 135
Source: Neumann 1985: 135
Source: Neumann 1985: 136
Source: Neumann 1985: 135