Hello and welcome Dan and Bella. She is a beautiful bird! I'm relatively new to greys too. From other posts I've read and from my own experience with Timber, they have very definite likes and dislikes. Time and trust will help as the others have said. However, Bella may never like to have her feet touched. As long as she can step up and down without issues, I'd avoid her feet. They all have their little quirks, which is one of the things that makes them so interesting. The fact that she allows you to scratch her head is a good sign and a pretty big deal (in my opinion). It is possible that she had a bad experience with someone holding her feet, a bad nail clip or who knows what. Greys never forget, so anything that happened to her in the first two years will stay with her. That is what all of us with a rehomed grey deal with. Their past experiences, good or bad, affect how we interact with them. Good luck and God bless