Hi goffredo, welcome to SoberRecovery.
Wow your girlfriend is so blessed having you in her life, that should help her so much more.
I agree with Dawn, this is up to her, all you can do is support and encourage her.....and take care of YOURSELF in the mean time.
Wishing you all the best on your new journey, please stay strong, this addiction thing is one heck of a hard road to travel...get support for yourself too.