I watched her speech today. In fact, I've watched it three times. My first reaction was, "Holy crap. She's freaking out." I watched it again,, paying careful attention to her vocal patterns. She's definitely under a ton of stress. I went off and watched a few of her other speeches on YouTube, then came back and watched this one a third time. There is something huge hanging over her had, and resigning is her only way out. She runs through that speech at breakneck speed, like she can't wait to be done with it and run away. She's also jittery, but the biggest tell is in her voice.
If you just want to watch one section, start at 3:10 and go to about 4:20.