My teacher told me that there was no creativity in art. I think she is wrong but am not sure. Is creativity allowed in art?

Far be it from me to undermine your teacher's authority, but she's just plain wrong. Art without creativity is impossible. Not only is creativity allowed in art, it is essential. It's true that some artworks show more creativity than others. It's also true that much of what passes these days for art is unoriginal or derivative. But it doesn't follow from this that there's no creativity involved at all in the production of art, not even in such a philistine age as ours.
Without trying to second guess your teacher, it would seem that what she's driving at is the notion that there's nothing new under the sun or that there's nothing truly original, nothing that hasn't already been done. There's certainly an element of truth to this argument, but even so, some measure of creativity must still be present in all but the most derivative of art works.
Why? Because the artist will always need to put something of him or herself into their work (unless they're flagrantly copying someone else's work, of course). If they're to make any kind of art work, however one wishes to define it, they cannot avoid being creative. Whether such creativity is put to good use is another matter entirely. Some works of art can display remarkable creativity without in any way moving or engaging the spectator. But creativity is there all the same, for the simple reason that the artist has put something of themselves into the work concerned.