Its really very scary, I was diagnosed 2 weeks before christmas with mixed dementia, im 53. The nights are worse for me, my mind go crazy wondering what is going to happen. I think im still in shock, as your wife will be too. Not sure how long she has known? I think I beat myself up and am expecting too much too soon. Its only because she is so frightened that she feels this way, its 1 hell of a thing to be told, its like drowning inside and not knowing how to come up for air.Having now had confirmation I have had endless bad nights with my wife's fears, she has asked me to promise that she would not referred to the hospital and is happy for the condition to take its natural coarse. I don't know what to do?
So sorry to read your news.
If you and your wife don't want any further medical tests then it isn't strictly necessary to have them. It is perfectly possible to get help from social services (if for example your wife needed help washing or dressing) without a diagnosis. They should asses what assistance your wife needs and offer help accordingly. The reason that she can or can't do something shouldn't make a difference.
If perhaps in the future your wife's condition changes in some way where medication could help you can always go back to the doctors at that point.
Best wishes for the future.