Runa actually noticed that Celeste was shy, and her presence made Celeste uncomfortable, but this was an optimal situation to extract information from the family.
The way Celeste looked at Runa when they first met told Runa that there was something between Celeste and Yohana. If Celeste could know what that was, she might be able to utilize it to destroy Yohana.
"I didn't get to know Celeste more than I would like to, Your Grace. I can't blame you if it's a matter of health because, at the end of the day, it is of the utmost importance to ensure her health before anything else," Runa began.
She had experience in flattering all sorts of diplomats and highly powerful people. Runa had a knack for reading into people's minds. Somehow, their feelings and desires were always bare in her eyes.