Among the bothersome (to me) aspects of this is the mother's obituary... wherein Tammy Jo Alexander is represented as deceased. I understand there's denial about how that came to be. Maybe the denial is legitimate. Maybe it is not legitimate....
Obituaries can often give good information, especially when written by a close family member. And in the case of a missing relative, they might give an indication of how the family feels regarding the disappearance without solid resolution. If the relative went missing recently, maybe Hope that they are still living would be reflected in their being described as a survivor. If years have gone by with no word, perhaps the family has come to accept that they died. Each case is different, as is the view taken by each family - but you cannot draw conclusions on the case itself from what an obituary says.
Also, be aware that some on-line "obituaries" are being written up by persons NOT associated with the family, and only drawing on information found on a headstone or in a funeral notice. These are usually very short and obvious, but sometimes contain errors and assumptions by the writer.