Your mother-in-law must have been deceived. Analysis: 1. Apart from the voluntary donation of some property for religious beliefs, there will be no other charges.
2. It is a lie that potion can cure all diseases, and it is a lie to those who are superstitious.
3. There should never be commercialized things in religion, because commercialization of religion is a kind of corruption and fall of religion!
I think your mother-in-law is superstitious and not religious, so you have to guide your mother-in-law to understand God correctly. Having faith is also a good thing. I am also a Christian, and I feel that Christianity is pretty good. You should also learn more about Christianity.
Bless you!