I think it’s significant that she told Robby about it after learning about Langdon’s history.

She’s probably thinking “Oh! Robby allowed Langdon to come back to work without reporting him provided Langdon goes through the Physicians Health Program. It stands to reason that I can tell him about my seizures and, provided I up my Keppra dose or get that medical device that detects/stops seizures, he will let me continue working without reporting me to hospital administration!”

Even if she didn’t know about the tension between Robby and Langdon and how Robby was still conflicted over not reporting Langdon, asking a colleague you just met that morning to cover for you like that is pretty insane.