What do Miss Kinnian's remarks suggest she is frightened about for Charlie's future?

Miss. Kinnian is worried that Charlie's new knowledge and experiences will put him in a position to be hurt emotionally. She also worries that the experiment might take a turn for the worse. The experiment was just that..... an unknown. The conclusion woud have to play itself out.... and in experiments, the end result is not a foregone conclusion.

People on the line who heard her turned to stare at me, and only when I nudged her to stop did she lower her voice. "I just hope to God," she whispered, "that you don't get hurt."

"I hope so," she said. "You have no idea how afraid I've been that something might go wrong. I feel partly responsible."