I don't know exactly what she studied but it was probably some combination of western and traditional Chinese medicine. The government of "The New China" has been highly supportive of the latter and trying to find a scientific basis for some of it with some success.

Folk religion includes other practices which are illegal under the Communist regime and were also illegal under Chiang Kai-Shek.

In Hubei province, for instance, a family with a troubled child might seek help from a "fox medium" who might attempt to divine the problem by inspecting the ashes from burnt incense and then, if that fails, be possessed by a fox spirit who will tell the people involved how it's going to be. If people don't play along they may be "haunted" for months which could partially be a matter of laying down a strong memory but is also not a difficult feat to accomplish in a culture where there are small and large fox shrines everywhere and everybody gets a fox figurine when they are born (which you will put on an altar together with your partner's when you get married.) Arraigning scenes in a small village isn't that hard, particularly if the fox has a network of confederates who owe the fox a favor or are otherwise in its power.

C's mom may very well have seen these practices be successful herself and almost certainly knew people who knew people who had been helped.

That was psychiatry for most of human existence, I mean we've had Freud for 120 years, decent psych drugs for 60. Similar practices have been documented in Africa, Polynesia, the Americas, etc. Here people get multiple psychiatric hospitalizations but never a real DX or RX. Here I saw pamphlet funded by a pharmaceutical company that made it sound as if, with his prescription pad, a doctor transforms Ritalin from a dangerous addictive drug to a safe ADHD treatment just like the priest at the Catholic church transforms bread and wine into the body and blood of Christ.

From a cross-cultural perspective our practices are a fad like everybody having gluten intolerance or autism and those practices are time tested. If I tried to do the same thing in modern North America, however, I'd have a much harder time.