Sorry, Filthiestfis, but your girlfriend still needs a Schengen visa to enter Italy. The page you link to only states that the paperwork to be completed by visa holders has been amended. It doesn't remove the actual requirement to obtain a visa.
The page states that persons entering the country need to complete this form, get it receipted, and then carry it with them (together with their passport):
http://www.interno.it/mininterno/export/sites/ default/it/assets/files/14/0798_2007_07_27_Dic hiarazione_di_presenza.pdf
(If you read the English translation, at the top right, you'll see that the form relates to 'foreign nationals who are entitled to stay in Italy for a period not exceeding three months or for the shorter period established in the
entry visa for visits, tourism, business and study'. i.e. it doesn't replace a visa. It simply provides additional paperwork).
The need for Peruvian citizens to obtain a Schengen visa is confirmed by the official visa page from the Italian government website:
http://www.esteri.it/visti/home_eng.asp
Chris