Below, she is almost there, and he still looks OK.
Below, she has arrived.
According to this, he has gone from waving to covering his face with his hand in 15 frames, which is 5 /6 second. She has done a complete 180 and is now looking at him squarely. In her testimony, she said he look "quizzical." Obviously, if his hand was over his face, he wouldn't look anything but covered. Her eyes remain on him, and when he goes into his spasms, she tries with two hands to get him to put down his arm. I wonder how hard she was pressing. Notice that Connally seems to be worse off than Kennedy. Notice that JFK's left fingers are flexed sharply at the metacarpal joints, all except his index finger, if that's real. Jackie is looking at Connally, probably because he was agonizing and vocalizing more. JFK wasn't vocalizing at all.
She continues looking at Connally as she leans in closer to JFK, who seems totally zombified, like he is mentally extracted. He is all clinched up; cognitively non-responsive. He seems frozen.
The heroic Nellie, who apparently was the most cognizant, starts pulling her husband down on top of herself to lower him, while Jackie's eyes go back to JFK, who remains frozen.
She huddled in very close to him at that point, but then when he was hit and went back and to the left, she ducked out of the way momentarily.
Then, she went back.
And then she climbed out the back, but later, she said she had no memory of doing it.