In my perfect world, Jenna would be released from prison and tell the Bobster: "Honey, I´ve been thinking a lot in there, and I realized I never loved you. I miss the big time living in Europe and being the Morgan Fairchild I always was. So kiss Charlie goodbye and bye-bye baby!"
So Jenna gives Bobby what he wants, and leaves the SF at last. She would prove to have a bit more of pride and character, just like the two previous incarnations. Besides, if Bobby was going to be killed, who wanted Jenna still in the show? Also this:
I wanted to post this particular scene but didn´t find it online. As many of you must remember, it was Jenna herself who noticed that Bobby didn´t seem to be too excited by the idea of marrying her. So she broke their engagement after Lucy´s departure in the "Swan Song" episode. Aside from being (probably) Presley´s best scene ever, it sort of implied that Bobby was allowed to do what he wanted the most: proposing to Pam again, which he did. So I think that he was morally ok with it. But it´s just my 2 cents. Of course, in real life everything might be different, but "Dallas" is not real life. It´s much better.