Hello and Welcome to Ask A Doctor service. I have reviewed your query and here is my advice. Tremors are non-intentional rhythmic movements of a body part(s). No diagnostic test confirms the condition. The diagnosis of a tremor is based on the doctor s examination of the child s movements. There is a hereditary form of tremor in which several family members are affected; there is another form in which only one family member has tremor. Tremors can happen after injury to brain, low blood sugar, and hyperthyroidism. Tremors can increase when the child has anxiety or fatigue. Since there are other neurologic conditions that resemble tremors, I suggest your grandchild be seen by a pediatric neurologist to verify that she does have a tremor, what type it is, prognosis, and does it require treatment. Hope I have answered your query. Let me know if I can assist you further.