The dose should be about 400 mg daily, but Canadian Family has raised a valid point about the necessity of hydration and the limits of small children. At this time I would agree that raising the dose to 250 is a good step, although inadequate. I would suggest using this dose for now and at the same time, making a great effort to train her towards a goal of sufficient hydration to handle the meds. Once she can take enough liquid daily, I would suggest raising the dose to 400, but split into two doses of 200 mg each and take morning and evening.