This is a revised copy of an entry recently made in my LiveJournal blog.
Katherine Parr, sixth wife of Henry VIII, failed to have a child by him. After his death she soon married Admiral Thomas Seymour and they had a daughter Mary on August 30 1548, but Katherine died in childbirth. Less than a year later Thomas Seymour was executed. Someone named CAWARDEN from Northumberland took the child back with him, raised her and married her off to a squire. Then she was forgotten, although both Mary and Elizabeth paid her an allowance till 1603 when records ceased.
The last two sentences are taken from a letter received in 2004 from Peg Mowat of Canada, a descendant of the Cardens of Brighton. I have not been able to find the source of Peg's information, nor any trace a Northumberland Cawarden.
At this time Thomas Cawarden of Bletchingly, knighted in 1545, was "Master of the King's Tents" and responsible for all festivals at court. He often used the name Carden, and was probably related to the Cawardens of Staffordshire. Perhaps it was he who arranged for someone to look after the child. Or perhaps it was Richard Carden, Dean of Chichester and chaplain to Henry VIII.
Andrew Millard kindly replied to the above blog, and as a result I have obtained from my local library a copy of Oxford, son of Queen Elizabeth I by Paul Streitz, published in USA 2001, ISBN 0-9713498-0-0. This amazing book (see the review at http://www.curledup.com/oxford.htm) is mostly devoted to claiming, rather plausibly, that the 17th Earl of Oxford was not only a son of Queen Elizabeth but used the pen name William Shake-speare and was responsible, rather than the "man from Stratford" for all the Shakespeare plays, sonnets and more.
Regarding the child of Katherine Parr, he says:
The existence of a second daughter for John de Vere [16th Earl of Oxford] first appeared in a will written by John de Vere in July 1562. This daughter's name, not unexpectedly, is "Mary." By any reasonable standards, this girl would be the missing Mary Seymour, daughter of Katherine Parr and Thomas Seymour. The inference is that William Cecil placed Mary Seymour in the household of John de Vere, as he had placed Oxford, child of Elizabeth. . . .
Streitz does not mention Carden or Cawarden, nor does he mention the allowance paid to the child until 1603.