Above can be used in the following ways:
1. as a preposition (followed by a noun)
The birds were flying high above the trees.
2. as an adverb (without a following noun)
She stared up at the stars above.
3. as an adjective
Please reply to the above address.
In “She’s above cheating on her exams.”, above here is used as a preposition, meaning too good for; it’s impossible for her to do such thing because she’s a morally good person.
Jason : Did you hear the rumor that Bryan stole his friend’s iPhone last year?
Michael: I don’t believe it. He’s a rich kid. His parents have enough money to buy him an iPhone.