Let's face the reality: she's not really that good. She did not play that well against Serena, and only won the match due to Serena's injuries. Even then, after Serena's injury timeout, she kept hitting the net a few times in a row.
At least last year she used to look good. Now, she looks more and more like Serena. Maybe they share the same pharmacist, who knows.
She has the physical condition to overpower many opponents, but she really needs to work on her groundstrokes. Lose those loopy topspin forehands that all teenage American players are thought by their USTA coaches, and learn to hit more winners.
Wilson BLX ProStaff 90: 368g, 7pHL, SW=352. (Wilson NXT 49lb / Lux AluPower 45lb).