With all due respect I don’t think she’s the one with the problem here. You can’t force your opinions on her and get mad when she doesn’t want to discuss it because its a heated topic. She can equally turn it around and provide research on the benefits of not having a foreskin. If you want to respect your friendship, you have to understand she has had a different upbringing and her life experiences that have shaped her values may be different to yours. Perhaps ask her about the benefits of some of her beliefs and why she believes this, she give you good reasons or she may start questioning them herself (like her belief about not having male friends etc). if you turn it around into a positive discussion, it will be easier for you both to learn from each other.