Galen sighed inwardly. He was afraid of this. He felt sorry for Anakin, as well. This was a terrible situation, and he couldn't have imagined being the one to break it to her as her Master.
Of course, he had his own revelation now. With a little inward breath to steady himself, he turned the chair around and sat in it properly, leaning forward to gently place his hands on her shoulders. "The name he took was Darth Vader. I told you I knew more than a few of the details..." His eyes closed briefly, battling back the disgust and self-loathing he felt for this, and then he continued, "I know them because Darth Vader was my Master." He didn't break eye contact with her as he said it, but he did remove his hands from her shoulders.