Cajun French, like many dialects, often uses more general terms for gender. They would likely use the French word "fille" (pronounced "fee") or "jeune fille" (pronounced "zhuh-n fi") which translates to "young girl".
It's also possible they'd use the more informal "petite" (pronounced "puh-teet") or "la petite" (pronounced "la puh-teet") which means "little one" or "the little one" and often refers to a young girl.