Jun 2020: "She wakes up early" is not accepted. Flagged.
Still not accepted
"She is up early" is not good enough?
Sie steht frue auf means she gets up early. Your abbreviated sentence does not allow for the verb "steht".
I suppose that'd be "Sie ist früh auf" (i.e. it's [unusually] early in the morning, and she is up and about already; we're not mentioning getting up, it's possible that she hasn't slept at all).
Why is "she rises early" not accepted?