What your relative is practicing comes from a Taoist belief that positive and negative emotions are associated with the internal organs.
"One of the keys to good health is to become aware of the emotional energies that reside in the organs, and to transform the negative emotional energies into positive virtues," this website explains.
"Taoists believe that we are all born with the virtues of love, gentleness, kindness, respect, honesty, fairness, justice, and righteousness. Unfortunately, as we mature and encounter more stress in our daily lives, negative emotions such as fear, anger, cruelty, impatience, worry, sadness, and grief often predominate. The negative emotions have deleterious effects on the internal organs and glands, draining our life-force and undermining our health."
These beliefs are based in pantheism and the alleged existence of a so-called universal life force that permeates all living things. This worldview is not compatible with Christianity.
I noticed that your relative is also involved in cranial sacral therapy which is considered to be a pseudoscience.
Physical therapy is solid profession but I'm afraid that just like what is happening in the field of therapeutic and sports massage, it is becoming infiltrated with half-baked New Age practices. For obvious reasons, this can only lead to a downgrade in the quality of service being offered to patients, and poses spiritual risks besides.