I just had a thought between the connection of the Jimbo scene one night followed by the Laureen scene the following night......if we are to assume that they were in fact on two consecutive nights....
If talk had got around the rodeo crowd about Jack, and his eye for men, well no doubt Laureen would have heard that talk too. So, I'm wondering if, because of her brazeness and forwardness, was she maybe one of these women who think, that she can turn a gay man straight. After all it was her who was doing the flirting and made the approach to Jack.
She was probably a natural flirt anyway, but if she had heard the rumours about Jack, then he would be a challenge and a bit of a trophy. A bit like, "well he might like men, but I'll give him a woman he wont resist".
Consequently, in the following years, if and when she ever had her suspicions about Jack and Ennis, she would not have been completely surprised about the fact, and realized that all those rumours back then on the rodeo cirucuit were true after all, and accepted Jack's lifestyle.
Maybe she even set up the meeting with him and Randall. She had obviosly became good friends with LaShawn and maybe she detected something from what she had said, and thought, that there may be a similarity between Randall and Jack.
As has been mentioned, Laureen was pretty street wise around men, what with the rodeo circuit and the business she was in. She would not have been bliind to what was going on around her, and she would be hearing things that most women would not be hearing.
I agree with Amanda, I like Laureen. I think she called a spade a spade, and I think she did that with Jack too.