I think Laureen would have had her suspicions about Jack. Her comment about Jack keeping his friends names in his head, indicated that maybe Jack had other male friends whom she had not met. I think the fact that Jack had said Brokeback was his favourite place, and then Ennis telling her that he and Jack had worked up there together years ago, probably told Laureen, that this one, Ennis, was obviously the one who Jack felt the closest to.
Jack had told Ennis that their sex life was practically non existent, so obviously that either waned over the years, or there was just no sexual feeling between the two of them. Most wives would get suspicious if their husband was no interested in sex with her, first off she would think of another woman, but if Jack had male friends only, that she had not met, sooner or later the penny would probbly drop, and once Laureen had suspicions that there were other men on the scene, she would be picking up on things a lot easier.
I think the way Laureen described the tyre blow out incident, it was said in a way, like, "I knew one day, something like this would happen"....and the way she recited the incident over the phone, was like a written script that she had worked out to tell people, whether they believed it or not, that was the story, and she was sticking to it.
It was her and her sons right to have half the ashes, so I dont think Ennis would ever have asked for them from her. I think he would have had more respect for her than to ask her that. I dont think he would have asked the Twists, if it had not been for Jacks request, and he seemed to accept OMT saying that Jack would be buried in the family plot. They were Jack's family after all and had that right.
Ennis was not the only one who lost someone, or who was mourning him....the Twists lost a son, Laureen lost a husband, and more importantly, Bobby lost a father.
If anything, the whole situation shows, that although the relationship Ennis and Jack had, was probably the most intimate and loving relationship out of all Jack's other relationships with his family...in the end, Ennis had no say in what happened to his lover, after he was gone.
I wonder if that was a comparison, to what can happen in other gay relationships that we have heard about, when one of them dies, the partner has no legal right to the same things, he would have, if they were legally married.