I also have very fair skin owing to my northern European ancestry. I regularly visit the dermatologist to make sure that I don't have any issues. I'm now in my 50's and while I am now very careful with exposure I'm afraid the damage is already done in my case.
We have a full bimini
, I always wear a hat, and I am religious about sunscreen - the highest rated I can find. Typically I use a zinc oxide sunscreen. I really don't think I could do this without lots of sunscreen. I'm afraid that your wife needs to keep using it even if she doesn't like it. You can find long sleeve shirts made by Columbia
and others that provide some sun protection. They advertise the SPF rating on the tag. I find that these are not uncomfortable in the heat. In addition I bought some product (I can't recall
the name but I'll try to look it up if you are interested) which you can use in your laundry
to "wash in" sun protection. I don't know if it really works or if its just snake oil
, but it can't hurt.
Good luck. I hope you can find a solution that works for you.