Most birds become more manageable with clipping, but there are a few that are very upset by it and go the other way. Unfortunately it sounds like Emma is one of those, but she becomes completely unmanageable if she's not clipped. When you have to get her clipped again, it might be helpful if you're not even in the same room so she doesn't associate it with you.

It's a month since I wrote this post, when I was feeling discouraged over Emma.
Since I moved my easy chair right close to her cage she has really warmed up. This morning she came over on her own and sat on my shoulder!

It's amazing how certain changes in the environment can make such a difference.