Wanders into this post 4 days late with Starbucks BUT

Pearl will politely decline a reward, feeling too uncomfortable with what she's learned and heard over the comms to accept anything.

Bilbo, after a lot of wrestling with his conscience and insisting that he honestly doesn't need any kind of reward, will finally accept a small ring of a dual Dark/Ghost typing that makes him invisible while wearing it. Those of the Dark type can still sense his presence even while he's invisible, however.