Thank you for your query.
It is good to know that Vyvanse
was working fine with your daughter for two weeks. However when you raised the dose to 50 mg. her appetite has come down. This is quite common with the drug. I would suggest that you discuss the issue with your doctor so that either the dose is reduced or some other cause for the loss of appetite is found.
As your daughter has been having a daily work out of tennis exercise is not the reason for the loss of appetite.
I hope I have responded to your query to your satisfaction.
Wishing your daughter all the best.