Regarding the FB page for SM,
If the family or atleast some of them also suspect BM
which IMO is more than likely considering what we can see happening with the searches ect,
and I'm sure the family know a lot more than we do right now such as BM's whereabouts around her dissapearance, when SM was last actually seen and I'm guessing many more facts we are not yet privvy too.
If this is the case it would be awfully difficult to update the FB page, asking for the publics help or even a general update!!
The silence here speaks volumes MOO