Well I guess it seems that Linux and macOS are out then…hmmm.
The unfortunate truth is that anyone using Windows is gonna end up on a bad trajectory in terms of security and privacy. @Ambrosio’s post demonstrates exactly that. So overall using Windows is a bad idea. I really hate being pessimistic in this kind of scenario, but that’s a harsh truth. Being a student, I know how much easier it is to just use Windows since most of my device activity is mainly for my studies, but I don’t want to stick to a harmful option either.
You could try using NextDNS and/or Safing Portmaster but I don’t expect these to have a strong impact in the long run. I’d say that it is a good idea to try and convince your wife to try Linux. You could buy a cheap laptop and just set up Linux Mint on it. Better if it doesn’t have an OS preinstalled. Or you could buy something like a Lenovo that comes with Linux out of the box (there are a few models sold with Linux pre-installed, probably with either Ubuntu or Fedora…Ubuntu is the base for LM so it should be pretty similar in terms of learning curve). That way your wife can have 2 separate devices, so her workflow can be separated and isolated. Do anything important on Linux Mint, and anything strictly work related which has no privacy repercussions on the Windows.