I just finished listening to the podcast and I'm afraid this story doesn't have a happy ending for Michelle.
Given that the informant who shared that Michelle had been killed and buried by the man who is currently behind bars was correct about the other crimes he committed, I think it is just a matter of time before they will be able to link Michelle's disappearance to him as well.
The fact that the girlfriend lied about Michelle spending the night at her house that night, and her being seen on camera following behind Michelle while carrying a bag, then returning alone later, tells me that it was most likely her who had agreed to meet that man to sell him something, and Michelle, armed with her gun, went along for protection. Knowing his alleged MO of meeting people to buy merchandise from FB Marketplace and then robbing/shooting the seller, I can easily see how this might have gone down. Michelle's girlfriend connects with this man on Marketplace to sell something, agrees to meet him somewhere to make the sale, Michelle goes along with her gun to ensure everything goes smoothly, this man tries to rob the women, Michelle pulls out her weapon (or tries) but he's faster, and she ends up dead and buried somewhere in a shallow grave.
The only thing I can't understand is why the girlfriend would just go back to her home and pretend nothing happened, and even lie about Michelle being there that night, instead of calling the police and reporting the murder. The only thing I can think is that she might have been selling something illegal (like a gun, as discussed in the podcast) and she was afraid of implicating herself in something criminal. I can't imagine letting someone get away with murder just to hide something like that, but I know people have covered their own behinds for less.
I hope Michelle's body is found soon, for her family's sake. Listening to her sister's voice break up while talking about the alleged killing/burying broke my heart.
IMO, MOO, etc., etc.