Julie,
This is fairly normal clown fish behaviour as they grow and become sexual.
All clown fish start off as neuter - i.e. neither male nor female. As they grow the largest/most dominant one will become male and then, as long as there is no more dominant fish, it will become female. The second most dominant one will become male and then stay male. Any subsequent ones will either stay neuter or become sexually immature males.
The female controls the group of clowns by being the most aggressive in the pack. Although it looks nasty it is rare for her to actually inflict injuries on the others unless there are too many where in the wild some would be driven out of the group.
Once they have established their pecking order they should settle down.
HTH, Eddie