Well firstly, did you guys get a picture of the ultrasound? I would go back to that inital picture and take it to another gi doc to look at. If there were stones in the gb in the picture then there must have been a flush involved. Did she do a gb flush w/ olive oil??? It could be that it got rid of all the stones. Another thing is that they "assumed" (which a lot of doctors do now a days) that she had gallstones based on the symptoms provided and her age.
If the gb was not the source of her original complaint...(which is??? Let us know) then other areas need to be looked at. The weakness could be a sign of one or two things:
surgery..What kind??? If it was laproscopic then recovery time should be better than the usual operation ( long cut).
If long cut, then she is porbably weak because of that . Also, I understand that food goes through the body a lot faster w/ out the gb, perhaps nutrients and vitamins are not being properly taken in by the intestines.
If this be the case, I would try purchesaing food enzymes. They are all natural and aide in the digestion process. Also, worst case scenerio...She is having internal bleeding, but this can be ruled out by taking her to the gi doctor and have he/she look at it. Other than than, it is not uncommon to be weak after a surgery of any kind.
Hope this helps...