Your cats internal alarm clock. Time to eat, sleep and play with their cat toys!
Cats are very habitual creatures. I don’t use an alarm clock because my cat, Mollie is there every morning waking me up at 6:00am. She sits on the nightstand and gently gives me a tap or two. My younger cat, Millie systematically sits by her cat toys each night when its time to play. If I don’t start swinging her sticks around so she could chase whatever is on the end of them, she will meow and jump on things that are off limits to her just to get my attention until I give in.
Your cats internal alarm clock and crepuscular nature tells her that it is time to get up at around dawn. It also keeps them up in the early evening. Usually mine sleep in the middle of the day. I do believe that their internal clock tells them when it’s time to eat, play, sleep etc. So if your cat is there every morning waking you up, it could really be a good thing especially if you forget to set your alarm clock. As long as she is not waking you up at 3:00am!