What you are describing sounds like an interdigital cyst. (Fancy way of saying betweent the toes) Many times theses cysts need to be curetted(scraped) out and the foot bandaged. You need to get her to stop licking them. Until you can get her to the doctor, you can keep it clean with betadine diluted 50% with water. You will also need an elizabethan collar(looks like a cone) to prevent her from licking until you can get her to the vet. If you have any antibiotic ointment such as neosporin, you can apply this to the area after cleaning with the betadine. Be careful though, greasy ointment may encourage her to lick more. You can try to put a child's sock over her foot to prevent the licking for now, but that usually isn't too successful. She should probably be on antibiotics until this has healed up. Once the doctor has evaluated her, he may suggest the foot be bandaged. Otherwise, leaving the foot open with a cone collar would be the other option which will allow you to be able to clean it and apply topical medication. You may want to ask your vet about dramamine or bonine for the car sickness. If he says it is ok, it may make the car ride a bit more tolerable. Best of luck to you and let me know if I can assist you further.