Ok, I have a little experience with this
I was with a guy who was Puerto Rican, I am total white girl! I don't speak the language, dance the dance, cook the food, nothing. We were together 10 years and engaged to each other. It was not the best relationship and I think cultural differences were a small part of the reason.
However along the way I met many americann women who were dating latino men. Some women immersed themselves into the culture so much that it became offensive even to me who was engaged to a latino man. Offensive because I felt these women were ashamed of who they really were, and ashamed of their own culture. So much so they had to take on another identity almost. Then there were women (like me) who loved their man and embracing his culture without turning into someone they were not. I learned a little spanish, learned how to cook a few meals, learned some of the ways of the culture so I would not offend them and in turn his family spoke english around me, made turkey on thanksgiving for me, etc... it was give and take.
Make sure he is as involved with YOU as you are with him. One day eat rice & beans and one day eat good ol' american spaghetti. Remember not lose yourself in his culture, take pride in who you are and your culture and also in your ability to adapt and learn other cultures and being able to keep an open mind and heart. Maybe your friend sees you slipping away into his culture to not lose him, he liked who you were when he met you. Listen to spanish with him and american music with her, keep up with both cultures and accomodate both, it will make you a richer person all around.
If she still has a problem with you just dating a latino man, then get rid of her, no need for small close-minded people in your life, no matter what their intentions are.
Hope I helped in some little way!