"She gets up early."
Translation:Sie steht früh auf.
"In the present tense, separable prefixes are separated from the verb and placed at the end of the sentence bracket."
Can you please give us the exact sentence where you got that? To get up simply cannot be translated as wecken. Your sie weckt früh doesn't even make sense without a target - whom she wakes. Yes, you can say she wakes early as an abbreviation of she awakes early but not in German.