Dear friend, welcome to HCM!
It is definitely not normal to have wide heart rate
It is mostly due to her Graves' disease.
She should take the advised dosages.
Regular medicines , checkups and TFTs are necessary for good control.
For jumping heart rate, you should ensure that the TFTs are controlled well too.
Take care and please keep me informed of your progress.
I hope to have answered your query satisfactorily.