What is the real story?..

What I want to know is, I've just seen "Murderous Maids" I saw "Sister my Sister" also, I watched them both back to to back. I would like to know how accurate these films really are, "Murderous Maids" delves more into Christine's relationship and childhood, whereas, "Sister my Sister" only shows the relationshp between the four women in the house. Also in "Murderous Maids' Christine works with another maid by the name of "Helene" in the Lancelin househould prior to Lea's arrival. This is not shown in "Sister my Sister", was there another maid that worked for the Lancelin's this is never mentioned. According to some critics reviews, "Murderous Maids" was considered more accurate then "Sister my Sister", also the Madam Lancelin portrayed in "Murderous Maids acted as a very respectable woman towards the sisters, she even spoke to them in a manner that was respectable and yet when I've read alot of info about the court case and the relationship with the Papin sisters and the Lancelin's, Madame Lancelin never spoke a word to the sisters in the seven years that they were employed in her household, she only passed notes and used hand gestures if she wanted something done this is portrayed in "Sister my Sister. So what is really accurate?, was Madame Lancelin a victim of her kindness as portrayed in "Murderous Maids? which is what Sylvie Testud says in her interview or was she the super callous bitch that was portrayed by Julie Walters in "Sister my Sister"? Are there any photos of Madame Lancelin and Genevieve of what they actually looked like before they were butchered to death?
BTW..I thought Sylvie Testud performance was outstanding, I would have liked to have seen more of the anxiety in Julie-Marie Parmentier (Lea's character) as was portrayed in Jodhi May's character in "Sister my Sister" as I understand that Lea did suffer from frequent anxiety attacks. Julie-Marie played the character a little bit subdued too calm and almsot too controlled IMO.