I don’t think she’d start outright crying, maybe trying to keep her composure. McCree sits down at the table, getting ready to eat himself. When Sombra starts eating, he lifts his head, about to ask her how she likes it until he realizes a few tears drop onto her plate. He brings it to her attention and even she doesn’t seem to have realized it. She quickly wipes her tears away, blaming some dust in her eyes. But even as she continues eating, the tears steadily keep coming. She puts down her fork, focusing on wiping her eyes despite the fact that the tears don’t appear to stop.
McCree watches as she does before he leaves his seat and walks over to her seat, gently grabbing her hand and has her stand. When he turns her to face him, he brings her against him, one hand holding the back of her head as the other wraps around her frame in a firm hug. Even before Sombra can understand it, it seems McCree’s seen it before (and has lived through it) and understands so he knows what she needs. He gives her another kiss to the top of her head, thanking her again for staying and that he won’t be going anywhere. He knows she’ll be okay when she finally mumbles for him to be quiet in a weak voice. The main thing he wants her to realize is that he’s glad that she’s with him.