6 months on...
I struggled after I finished GF2. I checked the " Country" and "Rock" lessons but they seemed too difficult for the level I was at. I needed a more progressive course, one that would build my finger's strenght and agility. I was a bit lost for a while, so I did a few songs, and kept playing Lisa's songs - I didn't stop practicing. But I was not satisfied, I seemed not to be making any progress, I felt that I was not playing those new songs very well, not enough precision, sound not outstanding, etc.
Then I checked the Blues section, which seemed less difficult (at least in the beginning), and eventually I checked the Acoustic section - and hurray, it was exactly what I needed. So I'm back on track now, having fun again, and feeling that this course will make me progress at my pace.
I think it would be a good idea to advise the beginners to go from GF1 and GF2 to Acoustic if they are struggling with the other courses.
The only real failure is the failure to try.