What was Regina thinking in this scene?

I always wondered what her opinion would be on Cady potentially crushing on Kevin. We all know she didn’t like Aaron, and she’s giving a smug smile here. Perhaps she’s thinking that now she can leave Aaron because Cady liked Kevin the whole time (Cady talked about mathletes way before Regina found out) and she doesn’t need to dangle him in front of her? Maybe she’s thinking about Cady lying to Aaron about hating maths? Just wondering…