Chinese Medicine is used to treat vitiligo, but it can be a very difficult condition to fully resolve. Treatment generally focuses more on herbal medicine than on needling or acupressure as they have little effect outside of strengthening the system as a whole. The general TCM principles are to tonify the Liver, Kidney, Blood and resolve wind. In TCM terms this is a deficiency condition and treatment works over time to resolve these relatively deep weaknesses in the body. The asthma that you mention can also be a sign of kidney deficiency.
For herbal formulas the following research may be helpful:
Effects of single herbal drugs on adhesion and migration of melanocytes.
A systematic review of natural health product treatment for vitiligo.
Because of the complexity of this condition, proper treatment would require her to be seen in person by a fully trained acupuncturist/herbalist in your area.