I'll tell you what. If my best friend were suspected of a horrible crime and I knew she was innocent I would be like a freaking pit bill trying to support her and protect her even to my own detriment.
I gave this some serious thought. I have a very dear friend who has supported me through more than one crisis. If she were accused of this crime, I would have believed in her innocence without question from day one. I would have been helping her turn over every stone, jog every memory, find any person who could corroborate her whereabouts, etc, etc.
If, in that process, those efforts did not pan out and a good alibi could not be found, and I also discovered that my friend did some of the things that TH did or is accused of doing -- the sexting, failing two polygraphs the mfh, the RO violation, etc. coupled with her overall demeanor, like carrying on about her hair color, commenting on news sites, posting nonchalantly on FB, giving the thumbs up about the situation with KH and baby K, etc., etc., I would wonder whether I really knew my friend, and I would tell her so. I would beg her to either give me an iron-clad reason why I should continue to believe her and an explanation about why she was behaving the way she was behaving, or come clean about what happened to her child. And I would mean it.
If she would not or could not do so, I would go to LE myself and tell them whatever I knew. If I'm wrong, I've lost my good friend, and that's my loss and deep regret. If I'm right, I've done everything I can to help both my friend and her child. I honestly believe that I would do the latter under these circumstances.
So all that having been said, I think DSS certainly, and maybe the others, too, would/should have come forward voluntarily by now. Either to help exculpate their friend, or to do the right thing if they thought she was involved. jmoo