Time lapse/Mary's child
There were two things I was wondering about.
I noticed that Betty's belly had grown quite a bit when she visited Mary and later commited suicide. Does that mean that there is a time lapse of several months from the moment when she was fired? It seemed so strange that her belly was so big all of a sudden. That would also mean that Rob was an outlaw for several months, although it seemed shorter in the film.
After being raped Mary is pregnant and doesn't know who the father is. Could it be that the scene of Rob & Mary at the standing stones is symbolical and meant to tell us, the audience, that Rob is the father? Didn't Mary say something like : "The stones make men hard and women fertile". Sounds like the perfect place to go to if you want to get pregnant.