I guessed its because of the water
some regions have soft and hard water http://www.eddy.uk.com/hard-water-regions.htm ,..and hard water can really dry the scalp and hair...I dont use very hot water on my hair to avoid dryness and damage...also, I would advice to try different brands of shampoo and conditioner ,she (your wife) will find one that will suit her,...I am using l'oreal and tresemme conditioner for my hair and once a month i do deep conditioning treatment.![]()