It's funny because the whole time she slept, she felt tired.
At first it was sporadic, but as time wore on she would be unconscious for days at a time, and then one day, she didn't wake up. And it stayed like that for a long time.
Weeks passed. Months.
She was unaware of the exterior world, instead tuned in solely to this battle raging within her, these dreams and thoughts and emotions that swelled internally. And on the outside, people tried to wake her, first casually and then in frustration, by the end they could not hide their panic.
Eventually, she began to sleep-walk, and that eased their worries. Allowed her to sleep in peace.