I have to be honest here and state that I never finished V.C. Andrews's Flowers in the Attic in print. I tried... oh, how I tried... but I just couldn't get into it. The same thing happened with all of the other books that girls my age loved, like Lurlene McDaniels's incredibly depressing stories - I had already moved on past those kinds of books to good stuff like L.J. Smith's Vampire Diaries series and Cate Tiernan's Sweep series by the time my peers were reading Flowers in the Attic and other "forbidden" books.
That said, I did know quite a bit about the book from friends, as well as all of the reasons that my mom gave me at the time for not allowing me to read it. (Not that I would have listened. I was/am very anti-censorship.) I also read the Wikipedia page for the book before watching the movie so I would know how true it was to the source material.
Hubby had no interest in watching this one, so I had to wait nearly a month after recording it to finally sit down and watch it by myself.
Flowers in the Attic was relatively true to the book but glossed over the worst bits of the story. I'm not sure why - Lifetime is for adults, it's not like the movie was shown in the Disney Channel.