There are a lot of theories about hot flashes and hence a number of things that will work for them. Estrogen is absolutely helpful for most women. But there is research showing that very deep abdominal breathing using biofeedback is also helpful. You can slow down your hot flashes at night if you turn up the temperature in your home or bedroom about an hour before you go to bed. You are likely to get more hot flashes during this hour, but far fewer during the night.
Exercise is also helpful in preventing hot flashes.
Vitamin E helps. Lonnie, many men write to me unable to cope with their wives' changes. I refer them to your book because yours is the only one I know of that has a chapter addressing the issues of the significant others of women in menopause. Most men won't read a book on menopause, but they'll read a chapter and it is helpful for them to understand what their woman is going through. Take her out to exercise or help her with activities so she can find time to exercise.