Her disappearing acts would have worried him sick. Not so much because he wanted to begrudge her a bit of rebellion -- Reeve's brother vanished as a child so he's easily triggered by people escaping his line of sight without explanation. Whether or not he informed Eirian's parents of her whereabouts, he probably made it a point to figure out where she was every time. Reeve wouldn't be able to sleep otherwise.
And if she ever wants to help out around the sanctuary, she's more than welcome. He just can't afford to pay her.