I agree that no matter the socio-economic status, or community standing of the molester, incest has most likely occurred since the beginning of humans. Tragically, it occurred to a relative of mine, and the mother, also my relative, did nothing. Despite a trip to the hospital, and injuries to a very young child which required surgery, and even though Child Protective Services got involved, my relative choose to believe whatever excuse her husband gave her. My personal opinion is that it was easier for her to believe what she wanted to believe because embracing the truth would have demanded a response from her that could have changed her life. So, it was easier to go on in her own version of reality because then she could stay with her husband, and not have to go on her own. Just my opinion, but it seems wives/mothers have a psychotic-like ability to not acknowledge what they don't want to know.
The relative who was the victim ( and later I believe her younger sister was designated her replacement) never had any children - probably because of the injuries she suffered - I don't know for certain. The younger sister is extremely obese, and overall this family demonstrates much dysfunction. Very tragic.