Out of interest had she been taking Ibuprofen or similar to try to climb through the pain? If so this could have been disrupting the healing process.
sounds like a tricky one... lateral solution - have you considered getting a new girlfriend?
I’d be asking the gp to run blood tests for inflammation. Multiple small joint pain in the fingers with stiffness of the joints worse in the morning, no specific trauma. Worth getting checked
Thanks yes sorry you already mentioned the climbing duration part. Anatomically it could be a bilateral lumbrical muscle issue but as a general rule of thumb if both hands are evenly affected then possibly some systemic inflammatory issue might be a main contributory factor or it is referred pain from the lower central neck region. It can still of course just be a local tissue problem in the hands. As mentioned have some blood tests checking for inflammatory markers. These issues and diagnosis with appropriate treatment should be pretty straight forward if you see the right person.