The Jewel Thief

You head to the museum in order to stop the jewel thief. You take to the roof of the building and see a woman in a tight leather catsuit (complete with cat ears), on all fours peering through the skylight, down at the large diamond below. You use your powers to prevent her noticing your presence. You watch her sway her ass back and forward like a happy cat shaking it's tail, while she waits for her moment to strike. As she watches the guard leave the room below she prepares to cut the glass on the skylight.
"Stop!" You command. And she stops dead in her tracks. "Stand up" She follows your instructions and stands up perfectly straight. "Turn around" She spins around to face you.
"Who are you, and how are you doing this?" She asks while pretending she's calm.
"Tell me what you're doing here"You already know, but you want a clear admission of guilt.
"I was going to steal that diamond." She tells your, without really wanting to.
"Tell me why."
"I'm a thief, it's what I do."