Years later, but...
I don't think Lureen loved Jack, but interestingly she shared many characteristics with Ennis.
It's Lureen who is the active partner in their first time of sex. It's Lureen who's quieter, seemingly happy punching away the numbers in her calculator, rather than facing up to his son's schooling problems, or her husbands mysterious trips away.
I think Lureen loves her father more than Jack. In many ways, Lureen acts like 'the son' that her father would be proud of. Running the business successfully. She even gives him the son he always wanted and the baby is presented to her father, as his! It's almost like Oedipus (or whatever the girl equivalent is) on heat!
The transformation from the vivacious red hair to the white haired porcelain doll is quite poignant too. It's almost as if the shock of discovering her sham marriage, literally turned her hair white! Lureen is such an active character in the first few scenes we see her, but towards the end, (charity dinner), and the phone call with Ennis, she looks literally fragile enough to smash into pieces!