questions with sugar

My girlfriend was talking about how she is always high after she eats. she takes the correct amount of insulin after she eats, but it does not come down for a while. She even tried using a little more to see if that would help but it didnt at all. Any ideas on why this might be?

[Farhaj]

What kind of insulin is she using.  Insilin after meals is usually calculated from carbs being consumed.  Usually a rapid acting insulin is taken after meals.  If she is using 70/30 or some variation, it might take longer for Blood sugar to come down.