Yes, they're designed to work through clothing. Also it's an intramuscular injection so it needs to be pretty deep into the muscle. With a normal IM injection if someone isn't quite in there and the medicine is in the surrounding tissue there may be some mild localized reaction (like irritation/discomfort) but it does eventually get absorbed into the tissue. With epi, you need that medicine taking effect 5 minutes ago, basically, so you're making sure it goes exactly where it needs to and all of it is in the muscle so it can quickly take effect and keep the person alive. Plus, as the above poster mentioned, it is made to be used even through clothes in an emergency.
My father is African as well and he speaks Arabic (multiple dialects), Berber, French, Spanish, German, Italian, and some Japanese. Several of those languages he sounds like a native speaker in. He's definitely a person who easily learns languages and accents and has a natural skill for it, it seems like Victoire does too.
I think especially with certain countries where people grow up speaking 2-3 languages because there are multiple national languages and school instruction and government records may be in one while everyone speaks another, it is probably more common for the average person to speak a few languages and thus easier if necessary to learn more, especially if they're related (like going from French to Spanish or Italian).