Sandra Kerr is usually at Whitby, maybe not for the whole week I don't know.
The Newcastle Folk Students do a showcase in the Spa theatre which she performs at. And last year I heard her in a group of female (and VERY feminist) singers. The year before it was Bagpuss (happy memories)
Why don't you contact the organisers and ask, I did when I found that they had dropped the accordion workshop (I'd noticed it the year I was buying one - they organised several the next year, maybe because I asked).
I noticed all those spaces available for workshop notices last year - personally I'd have prefered more information on existing offerings. There wasn't time to get to all of those.