She meets up with the Doctor after another few hours of Clara struggling over equations (at one point she'd said, "Clara, it might just be impossible to get calculations on time energy, don't you think?" and was shushed for her troubles). They hadn't planned it, but Rose had seen the sunset over the mountains and thought it would look better up closer. So she'd hiked over to the spot under the tree she'd gone to when she was mourning Jackie, and she found him there.
"Sunset?" she asks, and he nods without turning around. She leans against the tree next to him and watches it. Maybe this would be a good time to kiss, but the moment is already so perfect and simple that she thinks doing anything more would ruin it. Instead, she slips her fingers in between his and feels the warmth of his hand in hers, the squeeze of his hand.
As the sun sets, it grows colder, and he moves closer to her, their shoulders pressing together. By the time it's actually sunk beneath the horizon, her head rests on his shoulder, their hands still tightly wound together.
"You make me happy," she says simply. That was it, really. She could make her speeches, to them, but that was all there was to it - the warmth she felt that had nothing to do with the sun and everything to do with the man standing next to her.
"You too," he says back.
It never takes a declaration of love, a dramatic, tear-stricken, emotional scene about their feelings. That is about finding simplicity in a chaotic universe. Because what else could a chaotic universe crave but something simple?