"The windows" is her friend, and she's relatively tech savvy for a person of her generation.
Heck, people my mothers generation would not think to do this.
Heck, even my brother would not think to do this, or to look for this. If it's not a single place, if you have to open the command line (on windows) then the ability for a reasonable user to gain privacy is nonexistant.
the option might as well be a toggle switch in the middle of Tanzia, it will be noticed all the same.