In the time period civony is set in, people didn't live to be as old as this woman.
Also, kings married queens who are YOUNGER than they are for the purpose of bearing children, not ones who are already a quarter-century past menopause.
Don't get me wrong, I have nothing against the elderly. I only disagree with attempting to use them as sex objects.
With the arbitrary picture of breasts, you could imagine they were at least attached to a woman under 70.