My understanding is that she contacted the bishop IN ARIZONA after she had moved to Yreka and after Travis was murdered, for the purpose of finding out what he knew.
She would never have gone to the bishop and confessed while Travis was still alive because her bishop would then have promptly contacted Travis' bishop and Travis would be called in.
The fact that Travis went to his bishop and confessed after JA moved back to Yreka means that he 1)promised not to see her again, and 2) was put on probation (possibly disfellowshipped which means can't receive communion or bless people)...but he wasn't excommunicated because he came forth voluntarily. If he sinned again, he would certainly be excommunicated unless there were mitigating circumstances (such as being tied up and forced).
We see this in his behavior when he did not follow through on his plans to visit JA in Yreka. He was sincere in his repentance.
When you understand that Jodi might not have known Travis had been to his bishop, you begin to see how the motive was accelerated for the murder. She shows up and he rejects her sexual advances. Over the following hours she learns that Mimi Hall has replaced her on the Cancun trip. She already knows he wants to get married but perhaps thinks the secret travels/sexcapades are going to continue regardless-- until she finds out he has been to the bishop without telling her.
In Mormon culture, it is considered a betrayal to go to the bishop and confess without giving your partner the opportunity to do the same thing concurrently, and thereby avoiding a perpetrator/victim view of the fornication. If you each go to your separate bishops at the same time, or both go to one bishop, it goes much easier on you If you say you are setting a wedding date, it will go very easy on you. Chances are you will not even be disfellowshipped.
With Travis putting his membership in jeopardy if he has sex with JA again, that clearly points to JA's motive to fake a sex scene to go with the phone sex in order to blackmail TA into silence. At this point, she knows she will not remain his girlfriend or his dirty little secret because he is not going to give up his membership for her--no way. That would ruin him at PPL as well. And his ability to sell a book would be nil. An excommunicated person sometimes can't even get work in Utah and some parts of Idaho and Arizona.
Her only chance to continue to prey on Mormon men and meet wealthy ones who don't know her low class morals and social status, is to silence Travis. He foolishly has threatened to expose her to all their friends for the things she has done and the stalking, etc. He knows she is a sociopath but somehow does not know they are DANGEROUS. If he follows through with his threat, she is back to living off tips in her grandmother's extra bedroom.
This is why he had to die. He refused to be silenced and she knew one foolproof way to maintain her ability to continue the Mormon/PPL goldmine she discovered and that was to kill him.
I am sure jealousy was a factor but survival as a female bombshell predator feeding on these virginal returned missionaries was paramount, imo.
