Everyone here has claimed she is not legally diagnosed. My argument is that due to the nature of the case, the state can and will bring in a psychiatrist to examine her and build case study around evidence and testimony from her family and issue a determination of whether or not she is of sound mind. Which for a multitude of reasons, probably won't go in JF's favor. This where the multiple Livestreams and her public appearances and JFs own tweets will bite him in the ass and demonstrate a clear pattern of mentally disturbed behavior. The psychiatrist can issue a recommendation that Mama JF is not of sound mind to the judge. The judge can then grant her legal status as a mentally disabled individual for the purposes of this case.
From there, JF is pretty much screwed. He's the person who dropped her off and you can argue he purposefully endangered her wellbeing. If she's presumed dead, you can argue all kinds of charges. She's pretty much guaranteed to get retroactively diagnosed as a mentally ill person based on the Livestreams alone. However, this is all assuming they need to go this route at all.