Detail View of Queen Catherine Parr.

Lady Jane Grey by Master John, c. 1545, according to the book I scanned from.

However, it is now believed by the National Portrait Gallery to be that of Catherine Parr, Henry VIII's sixth and last wife.

"... the gallery has reidentified the portrait, thought to be by a Tudor artist known only as Master John, as being of Catherine Parr, sixth and last wife of Henry VIII. painted some time during the 1540s."

(at the bottom of the article)
"The distinctive crown shaped jewel which the sitter wears can be traced to an inventory of jewels belonging to Catherine Parr and the cameo beads appear to have belonged to Catherine Howard, from whom they would have passed to her successor as queen."

Image from the book The Life and Times of Elizabeth I, by Neville Williams (1972). Page #32. Shooting Star Press, Inc. New York, NY, USA. Printed 1995, ISBN 1-57335-246-2.

Reynalds, Nigel. The Lady Vanishes as Portrait of Jane Grey is Proved Wrong [Article], ©1996, Great Britain. Retrieved August 2, 2005 from the World Wide Web: http://www.britannia.com/history/ladyjane/portrait.html