Antagonists

At the moment, as I am readying myself to write a regional saga, I have been reading Josephine Cox's Born to Serve. This is an obviously very popular novel(as it has been reprinted about 20 times in the last 10 years) and Ms Cox is up in the best seller lists at the moment. but I have a problem with it -- the antagonist.

The villian of the piece is an evil woman who has no redeeming features, save her beautiful face. She also still lives with her mother who is supposed to be a saint. The reason she is so spoilt is supposed to come from her father, a father we learn in the course of the book who has been absent most of the girl's life. Um, I have a problem with that as the mother should bear some responsibility for how her child turned out. She is also a gently bred girl with a taste for sex -- a total opposite to her saintly mother. Yet there is no real explanation of how she became that way (ie saintly mother totally absorbed in other people's good works but neglecting child's needs). She just is. In my experience, people at some level do tend to absorb their parents' morals and ideals. I just didn't understand the motivation.

The heroine is sympathetic, but at points she is pathetic. Why would anyone stay in a household where the daughter of the house is clearly a nymphomaniac and has just seduced your finace away from you? And to top it off, she is willing to take a pay cut out of her meager earnings to help out the long suffering mother whom she admires but for exactly what reason I am not sure.
Then when the baby is born, the heroine decides she is going to take care of this child and protect it from the villian who shows no maternal feelings for the child. The net result is the villian become a cardboard cut out and the heroine starts to look pathetic. If the villian had been protrayed more sympathetically, given a few feelings of human decency, then the story would have resonated more with me.
So yes, Josephine Cox can write, but there were some major plot holes that I was not expecting to find in such a popular author.
I am also reading Ian Rankin's Witch Hunt. In this crime thriller, the Witch is given a few humanizing characteristics. It makes her all the more frightening for it. For me, creating an antagonist who is human is part of the battle. It helps make the protagonist's action more believeable.