How to stop the cat from whining?

My cat recently began to whine and wake me up early in the morning. I checked food and water and litter box and everything was fine. She woke me up, and went back to sleep by herself. I am so pissed off coz if I don't get enough sleep I cannot focus on work for a whole day.
Please share with me some useful tips. Otherwise I have to seriously consider sending her away.
Thanks