It appears she is having shivering and not chills and fever. Shivering is body's response when the body is exposed to cold environment. She should protect herself from cold by wearing adequate warm clothes, stay indoors in air conditioning, drink hot fluids and maintain hydration and maintain good nutrition.
Next Steps
If symptoms don't resolve with these measures or she develops fever, urinary problems or breathlessness palpitations or chest discomfort then she needs to consult a doctor urgently.
Health Tips
Stay warm, well hydrated, maintain good nutrition,