***SPOILER*** the documents should have revealed more

Rating: 7/10 (25 March 2013)

the premise for the story is fantastic but the makers should have worked harder to make things clearer (than the play) as the movie progressed. this is my own theory of what happened in the film. (BTW i totally think the movie has a lot in common with Japanese horror flicks including the ghost who is determined to stay evil and all the dead kids). Anyways, back to my own theories now:
when Kipps stays at the house overnight. he had access to a tonne of documentary evidence that could have been used to expand on why jennet's sister took her kid away and why she wouldn't let her see him.
I'm guessing most probably because jennet was already mentally unsound before the child was born and the child was born out of wedlock because the father did not want to marry a crazy chick or the affair was broken off before the wedding causing her to lose her mind. (the father's surname is on the birth certificate).
at the house, Kipps finds a picture of the Drablows where jennet is seen in one of the windows which would suggest that she lived with them. also, she hangs herself in the nursery at the same house which cements the fact that she was living there when the child was alive.
so why does she send Alice letters instead of saying things to her face?
since she was already living there, jennet might have had access to the child though she may not have been allowed to have him call her mom or to even get to meet the child often enough which might have strained her unsound mind even more.
now they never really showed how Nathaniel was left to sink into the marsh when everyone else survived. a boy of 7 is definitely agile enough to be able to jump over the back end of a coach or to hang onto his mother's enormous dress to avoid drowning.
and his body is found right in the middle of the carriage too which would suggest that he was probably incapacitated or sedated/really ill and was already on the floor of the carriage and not moving when the carriage was sinking.
since he wasn't accepting jennet as his mother, perhaps she drugged him/made him ill before this mishap occurred and since his body was never recovered, they couldn't confirm a poisoning or grave previous injury. or maybe jennet tricked him into eating something poisonous or jump off a floor or some other way tried to make him kill himself and Alice and her husband were just rushing him to a doctor when the carriage fell into the marsh. this would explain why jennet hates kids and has them kill themselves. she did it to her own kid too. and the guilt and the insanity made her blame her sister and commit suicide.
and the reason why she hates her sister is not because Alice doesn't let her see the child or give him her cards, it's because she is jealous of her and wants a husband, child, house, the whole shindig which her poor mental health and premarital affair and having a child out of wedlock made impossible.
jennet kills kids to exact revenge on happy families because she couldn't have one herself. and the reason why she keeps the souls of the kids with her is because none of them accept her as their mother (the daily's kid keeps visiting his mother)
however, in the end, the joke's on jennet as Joseph's soul is saved by the soul of his father and the family is reunited in death. in the end she shows her face and that of the other dead kids to Sam so he too becomes a believer and possibly starts to take his wife's claims that their dead son contacts her more seriously.
in the sequel, I'm guessing jennet and the kids haunt soldiers and they (adults) die which means that her curse (kids will die) was broken off by Kipps.