It makes sense to tackle the Bentonite on a large scale....as I've heard it's not the easiest to deal with.
Apparently it works well to get a bowl and a whisk and make a paste with a small amount of Bentonite and water...keep adding water and Bentonite until you get a consistency of thin yogurt or soymilk maybe.
Then she can use 1 tbsp of that liquid bentonite for each of her p&b shakes.