Hello Gary, Stimulant medications almost never effect growth, and when they do it's almost always from severe appetite suppression and weight loss.
Growth hormone is secreted at night, and children are on medications during the day.
The important thing is to follow someone's growth chart, as your daughter's pediatrician has. If someone is growing in height at the 50th percentile prior to starting medications, they should remain at the 50th percentile after taking medications. I'm usually not as concerned as much about weight, as long as someone isn't losing and as long as someone is growing in height. If their weight is also dropping, then increasing calorie and nutrition intake are the issue. Most of the time adjusting the timing of doses, changing medications, and using supplements takes care of the problem.