Actually, yes, this suggestion regarding the bowels makes sense. As I shift from my momentary preoccupation with concern here it occurs to me that a bitter, metallic taste in the mouth (especially in the morning) can be associated with biliary stasis. She does have issues with constipation and her liver, somewhat (though she's done a couple of recent colon hydrotherapy sessions...you'd think that would help). She might just need to get that train rolling.
I already knew about the vitamin C and the water piece is logical, also.