I must confess that I have never thought about Cassie's age before,but I find it an interesting subject.IMO,yes,she's in her mid twenties,but closer to her thirties than to her twenties,around 28 years old.Of course,she has youth's energy but not only because a person at this age can perfectly have it still,the same than in their first thirties and older still-on the contrary,that someone at this ages could lose it would be horrible ¡-;but specially because I have also considered her as a female Jack,as someone said about her in another thread long time ago and now Lance has just repeated in the post above.
Both of them are persons full with vital energy and hopes and strength in changing their lives for good and sexually aggressive,always taking the initiative.Moreover,in Cassie's case,this is increased for the life she has and the way she is living it;her behaviour while flirting with Ennis reveals that she is accustomed to this from some years ago.Surely for this reason,she has became bored of this environment and wants to have more chances to ameliorate it;during all these years,she could have saved enough money to get it,what can be obtained for a slightly older woman in this position...In sum,for me Cassie is a young but experienced woman who has already some "life" at her back.
No,it's not the age gap what separated her from Ennis,but his own and very personal troubles and problems.Cassie needed a man because,as someone also said once,she is as conventionalist in the end as Alma,but with her own way to show it.Ennis needed a woman to be a cover and,maybe he thought to be able to love her in his own style.But later he realised that wasn't going to happen,so he run away from her because he didn't want her to be unhappy as he made Alma be,even if without wanting it...Jack himself was surprised of this lack of "cover" before society when he asked him if he hadn't found "somebody" to marry in all those years.Both Ennis and Jack knew,although in their own ways,that their love was going nowhere in their social and cultural environment and that they needed to be two "normal" men,the way only a woman could allow them.It's sad,but it's the truth...