I would guess he has to make her feel at home in the new world, that's all he can offer. She has to come with acceptance that too much time would have passed, and everyone she knows is dead. And he has to offer her a place to belong.

Suggesting another avenue of research she can pursue might keep her treading water. "Yeah, so, something recently demonstrated to me that time travel using magic may be possible—maybe we can send you back to the exact moment you ended up here and shove you through the world-wall in the opposite direction while there's a hole there?" It barely even matters if it makes sense, so long as it gives her a straw to grasp at.