Well, no one could complain that Jaina Solo wasn't forward and that she didn't speak her mind. Obi-Wan was accustomed to some matter-of-fact conversations. But she was diverting all perfunctory pleasantries and getting right down into the heart of the matter.
Unfortunately, for her, Obi-Wan would not be able to provide a simple nor a quick answer to her confusion. Because, part of him, didn't even know the answer himself.
After closing the door to his room, he took a seat in the other chair. He waited until he found a comfortable position and then he looked to the carpet, as though he might see his answer written in the fibers of fabric and the strands of strings. He was mentally reliving the moment of her question. Anakin and himself both on Mustafar. He could almost feel the heat of the planet in the air as he remembered it. It had been a difficult place to breathe. It had been a nightmare.
"Please understand, if you can. And I know this is difficult because he is family to you."
He was family to Obi-Wan, as well.
"But I didn't leave Anakin on Mustafar. I left Vader there."