"I'm so sorry to hear that," she says, not wanting to say anything too radical as she notes at his change of tone. "Um... From my experience, it wouldn't have been too long for you to notice her spirit after... You can see me easily. Unless she's deliberately hiding, one should be able to find her if she has unfinished business."

Or if something happened to her to make her linger in the world. "Would it be rude to ask what...?"

Happened.