Ghastly, my Wife is the same way. I gave up trying to do anything to protect her computer. She even managed to get viruses passed Eset's stuff. She just figured the AV software would protect her computer and never gave a thought about doing anything more to protect her computer. She often asked why were paying for something that did not work. To some degree, she had a point.
I just isolated her computer on the LAN and when it gets a virus, I reformat and re-install the OS. I find the more often it has to be done, the more time goes by before it has to be done again. Re-installing the OS is quite a bit faster than trying to clean up the mess.
Recently she started asking about configuring her computer like mine, a little at a time. I might win this war yet.