There are definitely internship opportunities for Americans in France, I know for a fact that the French American Chamber of Commerce helps facilitate an internship program for Americans with private French companies in France...this includes fashion companies!!
I highly recommend that you learn French and get to the point where you're fluent. I learned to speak French fluently when I taught English there for 7 months to high school students through a program sponsored by the French government. They pay you a modest stipend, you get to live in France and get to know the culture and the language. Plus, you can use that time to make connections in the fashion industry. Since you're an English major, I think this might be interesting for you, only you should take some French classes so you have a better chance of being accepted. In my experience, once you have the language down, doors will open for you like you wouldn't expect.