Cathy has Windows 7 and does not want to move to Windows 10. Leo says that she can turn off recommended updates, but keep critical updates. Critical updates are vital to keeping the OS healthy and secure. But she can definitely choose to disable recommended updates, which is where the Windows 10 update files will be offered.
But there's a better option from Steve Gibson. It's called Never10. She can download it, install it, run it, and then can delete it. And she'll never be bothered by it again.