Coxsackie virus, unless it causes something like polio or Hepatitis A, is self-limiting and has no long-term effects. Most often, they aren't even treated.
The second part of this reaction sounds very much like seizure activity. You might not notice any major movements; seizures can be as tiny as fluttering eyes or as large as a whole body in spasm.
Seizures can have many types of triggers, be they certain lights, sounds, emotions, video games, etc. She is having a reaction to something that is then triggering seizure activity, I believe. She needs to see her doctor, but an EEG and some allergy testing wouldn't be out of line.
Keep close track of her activities, what she eats, where she goes, games she plays, a diary of sorts, and that could help to locate the trigger. They just aren't always obvious.
Let me know if you need further information. Please remember to click the accept button if this information is helpful. Thanks. JeanRN