Bonnie,

Perhaps there is no real need to worry if your daughter's dose is proportionate to her size.  You didn't mention how old she is or how big (height and weight), or if there were legitimate reasons for her doctor to believe she is still undersuppressed, despite the seemingly large dose.  The two websites that Chris D. mentioned up above are well worth a visit, if you want to know more about dosaging.  I recommend them highly!