Cynthia and Lesley, ( sisters !) Lets not be so harsh. Many of us have made this kind of error.( marrying men who thought they were God ) 
Seriously, I feel really sorry for her....she should have chummed up more with Claudia and escaped with her ! ...Very difficult with FOUR children ,all of whom probably adored their father. Maybe she couldn't bear to leave the kids and had to - er-surrender. Also , when you hang out with someone over a period of time you do grow fond of them despite their ( sometimes gruesome) flaws, and it's hard to make the break ( especially when the person you are leaving is full of vulnerabilities).
I met Marolyn a long time ago. Then she seemed ordinary, unpretencious and nice ( maybe a bit alone and lost but thats all guesswork on my part.).....and much of this thread is guesswork on all of our parts !