” Maybe it is the ashkenazi who is machmir because she is saying the bracha?”
To quote DY: “Ashkenazi hold she can do either.”
An Ashkenazi woman can choose whether or not to do the Mitzvah as well as whether or not she makes a bracha on it. A Sephardi woman might be able to choose whether or not to do the Mitzvah (although I’m not even sure about that), but she is NOT ALLOWED to make the bracha.