Blueduck
I wish that I had a specific answer for you. I do not know if you have read any of the information at the site on the link below. You may find some thing there that is helpfull.
For myself, after I have an attack I am scared to eat fats for a few days. I gradually add olive oil, which, for me at least, seems to be all right. I would not eat any regular "salad oil", I would think it is some kind of garbage oil that is not meant for human consumption in the first place, know what I mean ?
I avoid all fried foods, red meat, eggs, sugar, white flour products and processed foods after an attack. For some people coffee can bring on an attack. For some it is nuts or dairy. Maybe you can think back to what your Mother had eaten before she has attacks.
I do not know if the herbs you mention will expel stones or not. If they do, I have not heard of it, but that does not mean any thing. There is also a product called Stone Free that may help. Again, I am not sure.
I wish I could be of more help. Maybe some one else will come along and be able to help you better. I know that the gall bladder attacks are the most painful thing I have ever experienced and my sympathy goes out to your dear Mother.
Blueduck
http://www.sensiblehealth.com/