OK then, tell me her birthdate and where she lives. What do her parents do for a living? What school does she go to? Maybe I can wait outside it and get a picture ... (Eww.) Perhaps you or someone else CAN get this information, but it is harder if we do not know her real name. (It COULD be her real name, but I am suspicious of coincidences.) You are right, it is not complete anonymity, but it helps. I admit the lack of information about her could simply be because she only did one movie ... that we know of.
Anyone who knows her AND sees the movie or promotion for it will know that she is the one in the movie. But paparazzi and random internet trolls will have a harder time finding her. Promote her real name and the city she lives in and BOOM! She gets attention from all kinds of creeps. Fortunately, for most people if some information is not online then it is as if it does not exist.
I seem to remember in "Hannah Montana: The Movie" that her hometown folk agreed to keep Hannah / Miley's identity a secret from everyone else. Lou-Émilie's friends and family probably don't think her acting a big deal because it was only one movie. But all the time here at FLM, I see some members put out because they can not find more information about some actress who was in one movie 40 years ago, or who was briefly famous once but has seemingly disappeared. Their interest is most likely not malicious, but I say GOOD - let the woman have her anonymity. Not everyone craves celebrity.
David and deadman, I like both your takes on the movie. My memory on the details was not so clear, but thank you!