is my kitten overgrooming?

I recently adopted a 4 months old kitten and it’s my first experience with cats. Few times a day she starts to lick herself all over the body non stop for 15 minutes, and this had me worrying because it looks like an obsessive behavior rather than grooming. If I put my fingers in between while she is at it, she will keep licking my fingers instead of her body. Is this normal behavior?