Hello, I understand that you are concerned about Skittle's behavior because of some people's reaction to it and I'd like to help.
She sounds like a very sweet, submissive pup that is doing her best to get approval and affection from the people that she meets. Puppies greet, show submission and ask for food and attention from adults in their social group by licking their faces and necks. This is the way for them to affirm that they are no threat nor are they interested in changing their social status.
While her behavior is sweet with that understanding, we need to teach her that she doesn't need to be so submissive and she can still get attention.
We need to keep her mouth occupied so she cannot lick people while we teach her this. You can use a special ball, soft toy or kong toy that you can fill with peanut butter or cheese spread. Give this special toy to her only when she is greeting people. If she is holding a toy she cannot lick.
Expect her to get a little anxious with this, and she may repeatedly drop the toy and get a little frantic in her attempts to lick initially. This is a behavior that she has had for a long time and in her eyes it worked well to get her attention and make her subordinate position clear. But with repeated reinforcement and successful attention getting when she isn't licking she should learn.
Best of luck with your girl, it's clear she is sweet and well loved by you.