Hi
I would like to know the details of the illness.
What were the symptoms? Why were the blood tests done?
What are the other indices like 
Hemoglobin, MCV, MCHC, RDW in the CBC?
How high were the platelets and ESR?
Anemia is one of the causes where ESR and platelets are slightly high with low Hb and low 
RBC count. Most common cause of Anemia is 
Iron Deficiency. That is why your doctor would have suggested 
iron supplements. If iron deficiency is suspected, iron tonics should be given for 3 months. The one in formula is not sufficient.
And one needs to examine the child completely before commenting on what it could be.
Please do get back with all details. And if child is otherwise fine, we should not go behind treatment of lab values.
Best wishes.