It sounds to me like she may have an infection in her leg tissues known as cellulitis, and will need a course of antibiotics to clear it up. At the very least it sounds like stasis dermatitis which is another inflammation. This could be with or without an infection.
According to the Mayo Clinic:
Stasis dermatitis -- Stasis dermatitis usually affects the skin of the lower legs. It is associated with conditions (such as varicose veins and congestive heart failure) that cause blood and fluids to pool in the lower legs and prevent proper circulation. Stasis dermatitis may cause the skin around the ankles and over the shins to become discolored (red or brown), thick and itchy. Swelling may also be present. Since stasis dermatitis is caused by blood and fluids pooling in the lower legs, the goal of treatment is to correct the problem causing fluid buildup. Treatment may include elastic support hose (to help improve circulation of blood and other fluids), vein surgery and wet dressings.
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