Hello Friend, Good that you are seeking a help. Appreciate your interest to set few expectations clearly before marriage. Pre marriage assessments or counseling is a very good tool to handle such expectations and gaps between couples on the  interest related to careers, sexual life, financial planning, beliefs, foreign settlement, religious interests etc. So it's good to discuss as a holistic approach instead of sex as a single topics, then she should not feel bad about this. Feel free to reach out online through Practo app for any further assistance.

Hi, Nice question. It's totally up to you. By now you must be knowing her and her comfort level to talk about these issues. U can start talking about subtle intimate things and if she is comfortable slowly proceed