She is only allowed to fly to her destination, not anywhere else. She notices that she is not where she should be, that she cannot progress to where she was told to go, and she careens out of control when her wings won't flap anymore, and she crashes.
Well, out of the range of possible responses to that, he thinks he'll go with...
"Um, do you need help?"
"I'm going to interpret that as a yes." He considers available resources. "In the realm of things I can get you quickly: food? Water? Painkillers?"
He goes into the house.
She isn't usually allowed to go wherever she wants, but she can in fact follow him right now. She does.
A couple of turns through the very mortal house, and they arrive in a very mortal kitchen, where her very mortal guide (who is a little shorter than she is - aren't mortals supposed to be large?) fills a glass with water and leaves it on the counter while he fetches a box of pastries out of a cupboard. (The kitchen is definitely built for people larger than this particular mortal.)
"Okay," says the mortal, picking up the glass and holding it for her to drink from, "something is definitely going on here that I don't understand. Multiple things that I don't understand are going on here."
He smiles wryly at the blink, and keeps holding the water for her. "Which first: painkillers, or attempting to communicate about the nature of your problem?"
"Second thing?" he guesses. "All right. You seem constrained rather than impaired..."
"I confess I am not oversupplied with theories about how that could come to be. But I would like to unconstrain you if possible," says the mortal.
"So. What do I know..." he muses out loud. "You have wings and you fell out of thin air and you weigh much less than I'd expect from a human of your size. And you can hear and understand speech and walk and sip and chew but you seem to be constrained from speaking and gesturing and feeding yourself...?"
"I suspect there is a way to unconstrain you. Given the emphatic blink, I also suspect that the food had something to do with it. But clearly it hasn't solved the entire problem just yet."