My stutter came back pretty much overnight too, in connection with a psychological crash I experienced - nothing major, just a feeling of resignation that set in about my medical issues. As it is in my case, it will improve over time and possibly with changes in lifestyle (lockdown has been tough - with the gyms opening back up that has helped, as has getting back into singing, etc.). And yes, we're all still here. I beat it 6-7 years ago in my teens, and will beat it again as an adult - so will your GF. All the best to ya both.