This is the 7121st most frequent French word.
millie
"Millie" is not a standard French word. It may be a misspelling or a proper noun.
Here, 'Millie' is a proper noun used as someone's name.
Millie est une élève très studieuse dans notre classe.
Millie is a very studious student in our class.
In this context, 'Millie' continues to be a proper noun referring to an individual.
Une fois, Millie a partagé son goûter avec ses amis.
Once, Millie shared her snack with her friends.
Here, 'Millie' is again used as a proper name, signifying the subject performing the action.