Hi There,
I have no clue why i am thinking of giving advise as i am complete novice myself but ihad same problem for a moment, Lisa does demonstrate a pinky G that some might find more suited to there individual type, but decided i wanted to learn by the book and master the proper G as i call it and soon realized that if i move my thumb position very very slightly it became a lot easier especially when needing to change to a C more quickly. try it it worked for me Hope Lisa does not come on and tell me off for my advice lol