I get an INTJ vibe from her.... so articulate and disciplined in her speech. Her word selection is flawless, never says anything the politicians can criticize her on, it's impressive. (i've seen just about all her press conferences, not just that video up there)
I'd go a step farther and say the last three fed chiefs have been INTX. That's really not a bias if you think about the natural self-selection mechanisms at play.... IE, NTs absolutely love economics, and the INT will make it a serious lifelong pursuit towards mastery.