In addition to mcparadise’s good advice, I want to add another little factoid:
The installation of after-market equipment like a turbocharger will void the car’s Powertrain Warranty.
Since the stresses imposed by the turbocharger will likely shorten the life of the engine, I think that it is very short-sighted to lose the protection of that warranty. This could turn into a real money-pit, especially if the girl is very “enthusiastic” in using the power boost of that turbocharger.
Add in the loss of fuel efficiency, the necessity of using premium gas, and a likely increase in emissions, and I think that adding a turbocharger to that Civic would not be a good idea.