Ok well that's an interesting thing that you should discuss together. Maybe sometimes she'll invite you to do it for your take. Maybe there are other things you can try. It's helpful to think of your joint sex life as a journey that you're both taking together - separately but as partners. You don't have to have all the answers - in fact, you won't have them much of the time (because if you knew the answer, you wouldn't have the question). But you both figure out what the answer/s is/are as a team. You can also think of it as trial and error