Thank you for your question
My name is Clare and I shall do my best to help you
I am sorry that you have had this extra pressure at this time.
The action that will be taken (if any) is taken against your wife as the person involved, but is dealt with and settled by Aviva who are her insurers.
The letter (and any action) is sent to her - but it is Aviva who will actually deal with it.
All you need to do is pass the letter to them and ask them to deal with it.
Please ask if you need further details
If Aviva are negligent and do nothing then yes there is a chance that your wife could receive a c= Court Claim.
You would then have to deal with it as her "litigation friend" - while making sure that Aviva starts to do what they are paid for!
You ar every welcome and I hope that Aviva act appropriately - and I am so very sorry for your troubles