That's the impression I got too. However, I do think Edmund knows that things haven't really changed as far as Mrs. Norris goes. In life, we cannot all avoid unpleasant, even nasty, people. Fanny was feeling desperate about having to go and live with Mrs. Norris. Would it really help her if her joined her in wringing his hands and panicking? I maintain that he wasn't being blind, but just trying to help her.