Marrying close relatives of a previous wife was actually VERY common. Of course this would happen after the DEATH of the first wife. This was very common until very recently. My own your great grandfather (1883 - 1926) married his wife's SISTER, after her untimely death. In some families marrying cousins was VERY common.**1 This STILL happens, but to a much lesser degree.
Funny situation in my wife's family. A large family where the younger children are nearly the same age as the oldest grandchildren.**2 So her cousin and a cousin's SON married two SISTERS. It work's out that one sister is the AUNT of her... brother in-law.
**1 - Until the danger of this tradition became known. There's practically NO medical problem to marry a first cousin. The problems start when this happens again and again, over generations, in the same family,
**2 - It was rather surreal seeing a mother and daughter sitting together, nursing their children.
