Hi,
She sounds like a sweetheart and you have obviously done a fantastic job of socialising her. Her licking everybody is a natural greeting and shows that she sees everyone as non threatening and higher on the dominance scale than her - perfect. She is happy with her place in life and must be an absolute joy to own.
I would suggest only letting her greet people who are willing to get up and move away as soon as she starts to lick until the problem is overcome. Another trick I have used with labs is to train them to hold a toy when greeting people and then they are unable to lick!!