To me, it's NOT her age... Her attitude--her sense of need, her maturity, her sensuality, and a few other attributes are FAR more important than her age. Finding a woman who appreciates a man (notice NO reference to ethnicity here) for his ability to provide the sexual fulfillment that she may have missed out on for many years in a marriage or other m/f relationship is like finding a jewel. If she has been unhappily married (with or without kids) and recognizes that her happiness is going to depend on HER making some choices, then that woman is very likely to go overboard (metaphorically speaking) in her efforts to give, and continue to give to the one who she begins to explore with, sexually. Age doesn't usually figure into most of that.
A sexual relationship with such a woman, carefully nurtured, and discreetly carried out by two mature adults, can be intensely exciting and fulfilling.
The other factors (risk management, guilt feelings, legal ramifications, etc)? Well, that's another thread, isn't it?