She noticed that her hand trembled slightly as it held the tiny cup of liquid and she made an effort to hold it steady. Did he realize the effect he had on her? How deeply everything he said seemed to strike? He made her want to hold him at arms length at the same time that she wanted to crush herself against him. It wasn't anything she really understood, but when he looked at her, she felt like he owned her in a way that no living creature ever had. Did he know how easily he could have crushed her? How simple it would be for him to destroy her with a single word? And yet here he was, admitting that he cared about her as more than someone who looked after him. More than he cared for the Winchesters even. She was self centered enough to feel ridiculously smug about that. She wondered if she'd ever get the chance to rub that in poor little Dean's face.
The box she'd locked her feelings in rattled, and for once, she didn't ignore it. What he did to her, the feelings he caused in her, they were worth her attention. She'd never tell him, that much she knew. But she could at least take the time to tell herself. It wasn't that she didn't want him to know, it as that she couldn't give herself up to him. Not like that. Not ever. She was far too damaged for that.
In her mind, she told him she loved him. She said it plainly, without emphasis or undo emotion. It was a fact, and she stated it. But only in her mind. Out loud, she merely said "Thank you."
Carefully, she slid her arm behind his shoulders and raised him up just a little and held the small cup to his lips for him to drink.