Hi Pixie,
I have gotten my blood pressure back down to the normal range by following Dr. Clark's Protocol. What she has found is that always, when there is high blood pressure, there is cadmium build up in the kidneys, so yes, a good kidney flush would be extremely helpful for your mom, I think. Also, although she drinks lots of water, is it clean water?? The biggest source of cadmium contamination is drinking tap water with it's seepage from metal pipes in the home. Filtering it with something like a britta filter is good, but Dr. Clark has found that the heavy metals, like cadmium, will build up quite quickly in the filter and you would need to change it about once a week. So I've found that the drinking water in the grocery stores are about the best as long as you avoid any contact with the solvent-cleaned dispensing spout. :)
Or she might want to convert the metal pipes in the house over to pvc ones, as a more permanent solution.