Is this possible? Or did you mean she was fair (blond) skinned with dark hair on her head and crotch?
This is definitely possible. There are different types of hair.
1---Hair on the head which grows more or less continuously. Facial hair in men grows continuously after puberty.
2---Body hair--chest, back, arms, legs
5---Eyebrows and eyelashes
Body, pubic and axillary hair is under significant hormonal control regarding when the hair appears in the person's development.
Body, pubic, axillary and eyebrow/eyelash hair grows to a certain length and then falls out to be replaced by a new hair shaft. Facial hair in boys and men grows continuously to unlimited length after puberty with a small number of hair shafts slowly being replaced.
The amount of melanin in each part of the body determines what color the hair will be.
There are also different forms of hair: fetal lanugo hair, vellus hair (peach fuzz) and terminal hair which is longer and coarser.