How many weeks should laser hair removal sessions be spaced out for face and neck/hair line?

I have recently started getting laser hair removal for face an neck. I have had 2x sessions so far and each have ben spaced 2 weeks apart. Is this normal? I thought it was meant to be at least 6 weeks apart? Will going in earlier be wasting my time or money? My hair on my face grows quite slowly, so by the time i go in, only the very tip of the thicker hairs have JUST come through where as alot of them are still beneath the surface. She said after my 3rd session, she will space them 3 weeks apart