In a message to her fans she said on her website: "As you know, I love Brown and I love studying pretty much more than anything. But recently I've had so much to juggle that being a student AND fulfilling my other commitments has become a little impossible.
"I've decided to take a bit of time off to completely finish my work on Harry Potter and to focus on my other professional and acting projects."
The next Harry Potter film is due out this summer.