Thanks for all the responses! Seems like the normal reaction is just a few days which is what I had too. After initially looking like she was improving my wife is still suffering with fatigue and the headache has now come back (4.5 weeks later) so is going back to the doctor
Whilst wouldn't wish the reaction shes had on anyone else, would be nice to know she wasn't alone and/or it does get better with time but haven't yet found anyone with a similar reaction so she really has been unlucky.
If it helps, I suffered with some cracking headaches and fatigue about a week after I had the jab. That lasted for a good week or so and appears to have cleared up.