My Wife (58) Is In Excellent Health. She Felt Fine

My wife (58) is in excellent health. She felt fine this morning, around 11 am came down full body achiness, full body chills, very nauseous. No sore throat, no congestion, no runny nose, no cold symptoms. She had a flu shot 4 weeks ago. Normal bm around 1:30 this afternoon. This morning she had scrambled eggs and fruit outside of the house. Thoughts? Any thing she can take? thank you.