Some of the reviewers here obviously have never heard of, or read a book of, historical fiction. This movie did not begin with "True Story". Hence why expect it to be? Indeed, if a film about historical events was 100% accurate it would be so boring we'd then complain about that.
Gretchen Mol did a superb job as usual. I first saw her in "Forever Mine". If she gets the right part she always delivers. The part of the young man was also well done. It is difficult to give much info without spoiling the plot. It has drama, romance and tragedy. All well done; the components of good movies. So watch it for yourself. And don't try to make historical comparisons as you do. That's not what this movie is about.
Most of the bad reviews here come from those who did not see the typical Hollywood template film they expected. There are no Quentin Tarantino type influences here. It's not the typical American type template that has won the US only 5 Palm D Ors in drama at Cannes in the last 25 years even though we've put out tens of thousands of films! Yes if you expect the usual steamy sex, filthy talk, things blowing up, chase scenes, gun battles and bloody gore-filled murder scenes you will be disappointed.
Sadly, there are few American made movies worth the time or expense at a cinema these days but this is one of them. You get to have your cake and eat it too.