Who am I?

I've seen and photographed lots of stained glass this year but this has to be one of my favourite pieces. Its a 15th century roundel depicting the face of a lady using silver stain. Although quite corroded its still quite beautiful and its wonderful that the eyes have survived so well. But who is she? My first thought was that this could be Alice Chaucer, Duchess of Suffolk and granddaughter of the poet Geoffrey Chaucer. The dates would be right and the window is right next to Alice's tomb (although the glass may have been moved there from elsewhere in the church). But, comparing Alice's effigy on the tomb with the face suggests that its not her - Alice had a long thin face and a long nose. The design appears to include a nimbus which might suggest a saint. So, it could be St Catherine, who is often portrayed with a crown or St Anne who sometimes appears with a crown. I think a good argument can be made for Anne since Alice Chaucer was a significant patron of the arts and particularly of works depicting St Anne.  Whoever it is I think its a glorious piece.