She saw it as she assigned them tasks, told them who would go; whole would stay. Saw the way Mac subtly shifted towards Jack when she said their names. Saw their eyes meet and the whole convo that went between them with eyes and subtle signs alike.
Don't get her wrong now, she understood some of the body's language, she *was* an expert spy of course. But when Mac tilted his head, half closed his eyes, and sighed while running his hand up his arm, well she was confused. Without the arm thing she could infer that Mac was annoyed at her talking, he just wanted to go. But that was more Jack's thing than the young Agent she had come to know and love. He always listened before running off.
But Jack would wiggle his fingers on his right hand, give him a wink, and a shoulder shrug and that would make Mac crack a barely there smile but one all the same.
She knew their history. Knew their bond had been formed during some of the worst times in this blasted war their country was still fighting, she knew that a bond like that was hard pressed to find and with it went some equally weird ways of communicating, but; when she watched them...She really wished she could understand a bit more about her agents than their paper files said.