First, you don?t get chicken pox from chickens! It is a human condition caused by a herpes virus (similar to the one that causes cold sores).
Your pup?s problem is called impetigo, which is more like juvenile acne in adolescent youths.
Sometimes associated with poor management, (such as dirty bedding or inadequate nutrition), impetigo is fairly common and caused by Staphylococcal bacteria.
Most mild cases resolve spontaneously without treatment around the time of sexual maturity but your pup does look quite severely affected.
Chlorhexidine shampoos, antibiotic gels and, occasionally, oral antibiotics should do the trick.
Dog bedding should be washed regularly as it will be teeming with bugs and check that her diet has some essential fatty acids in it.