Obviously, I can only 'speculate', but my personal opinion is she wants the distinction of killing Travis for herself; she doesn't like sharing the spotlight. Stabbing Travis was extremely personal, and having fognesia allows her to keep the details for herself, this is her trophy.
Creating stories and/or using other people for her benefit, has been her way her whole life. She is a sociopath, playing with people's minds is what she does.
The defense wants us to try and 'understand' why she did this, and see her as a victim, most of us can't fathom pure evil, so we want to find the WHY... The state needs to remind the jury her mind is not human.
Accomplice, gun, knife, camera, journals, texts, many of this is nothing but brilliant distractions; she murdered him in cold blood....she didn't even cover up the man she loved, but left him in a cold, wet shower.... SICK