Thanks for posting your query.
Your child is most probably suffering from a scalp dermatitis
which can be related to her colds as in case of atopic dermatitis
or a result of nutritional deficiencies which can affect her overall health.
The best way to confirm would be to get her evaluated by your doctor who can start prescription medications ( anti allergens, emollients , antibiotics if needed )appropriately .
Meanwhile make sure her scalp is not exposed to sun and extreme dry conditions .give her a nutritious diet rich in vitamin c
, zinc. And proteins or a prescription multivitamin
Wishing your child a speedy recovery.