Mary reached out across the bench and took his hand in hers to squeeze it, giving him a smile when he looked up at her again. "You've made me food," Mary told him warmly, even if her voice was still a little thick from crying. "Right now you've done everything for me." She didn't want any mortal to feel that they owed her anything.
The only reason Mary wasn't already jamming fries into her mouth was because they'd be too hot. And Mary wanted to avoid anything that felt like her throat being on fire for a long while.