Women's Rights: Yes its wrong to be paid less for equal work. Yes you have a valid complaint and may have options to fix the problem.
However, I suggest you do nothing and just suck-it-up. I know that is not what you want to hear and may be unpopular but there it is. I'm a cautious man with perhaps a touch of paranoia, but also one with some business world experience. Many managers are willing to stab you in the back at a moment's notice and they don't have to explain themselves to anyone.
You are an intern, you have no power and are greatly dependent on the good wishes of your superiors. You want a good grade and credit for your work (and letters of recommendation, maybe even a job offer from the company.) You want the company to sing your praises when future HR staff call and ask about the application you just handed them. You don't want to be fired or even to be thought ill of.
Your bosses have you tightly in their grip. Grin and bear the slight until the internship is over and you got what you came for. The internship can be multiple wins for your career development and progression, don't darken it or make it a negative. You are in a fragile situation, BE CAREFUL. Do not rock the boat. Don't let your pride slash a hole in what you're building.
It's a bit like visiting a museum. The museum can offer wonderful things to you, but you have to be quiet, walk slowly and don't touch anything. Make a disturbance and you can be thrown out and asked not to return.
-Doughdee222
"I am a realist, not a pessimist. The real world is pessimistic by nature."