I heard long ago that dogs can get teenage spots. I mention this because my one year old lurcher has a spot..I'm indecisive what it is..whether it is such a teenage thing..an ingrown hair etc she has a vet appt next week anyway..but do teenage spots in dogs exist???.
Where is the spot? If on the muzzle it could just be an infected hair follicle. In the early 80's, my young (about 10m) Cavalier male had a series of pimples on his inner thighs, nothing serious but I took him to the vet. I was told that it was acne, and was due to changes in his hormone levels. At that time he was treated with a short course of mild steroids, which I was a bit iffy about, but they did do the trick.
It is on her lip area carole. So could be a hair follicle like you said.its not bothering her but see what the vet says next week