Just ask her to dress in regular civvie clothes and to carry a clipboard or document folder which will make it look as though she’s there to sell you something (!) or any number of legit reasons.
Avoid tourers or Roms, try and stick with a well reviewed local who is likely to be more trustworthy.
Limit access to one or two rooms, hide any valuables, phone, tablet, etc, and have the right amount of cash tucked away somewhere handy. All common sense. Go for it.