It's probably something done from anxiety or boredom. My sheltie mix is an obsessive licker. Once he starts, he will NOT stop. I have to divert his attention to something else if I want him to stop. I'd suggest your friend do that...like give a chew toy or something and praise her if she licks/chews/plays with it.
Physical play and exercise and teaching tricks might help, too. Burn some energy if it's boredom and/or divert attention from the licking (snap the mind out of it).
__________________ Terri, proud mom to Mandie  & Shelby-Dale  |