I think there's a discussion somewhere on the possibility of George Boleyn having illegitimate children.His father, Thomas Boleyn had 3 siblings: James, Margaret and Anne.I have no information on James past the death year of 1561.Margaret married John Sackville. She died in 1533. Her son was Richard Sackville who married Winifred Brydges. He died in 1566, she in 1586. They had at least 2 children, Thomas and Anne. Thomas Sackville became Baron Buckhurst, 1st earl of Dorset. He died in 1608. Thomas's sister Anne married Gregory Fiennes, 10th Baron Dacre. Anne died in 1595 leaving no known living children.Thomas's other sister Anne married John Shelton. They had two children, John and Mary. John (junior) married Margaret Parker, sister of Jane Parker Boleyn, Lady Rochford. They had two children, Mary and Ralph. This Mary was Mary Shelton Scudamore who served Queen Elizabeth. Mary's marriage to John Scudamore was the catalyst for the story that Elizabeth broke Mary Shelton's finger - at least according to Mary Queen of Scots. Eleanor Bridges writing to the Earl of Rutland in 1576 said "the Queen has used Mary Shelton very ill for her marriage. “She hath telt liberall bothe with bloes and yevell wordes, and hath not yet graunted her consent.” No one ever bought her husband more dearly."Unfortunately I have no information on Ralph. Are you looking for heirs to the earldom of Ormond in the male line? As far as I know James Boleyn, Thomas's brother held the title of 7th earl of Ormond through his mother's line. In 1597 George Carey, 2nd baron Hunsdon and grandson of Mary Boleyn, Queen Anne's sister, considered claiming the Ormond earldom but did not pursue it. Elizabeth Sheffield, niece of Charles Howard 2nd baron Effingham (married to Katherine Carey, daughter of Henry Carey and Anne Morgan) had married the 10th earl of Ormond, Thomas Butler in 1583 so this title came back into the extended family but not directly to the Carey/Knollys branch of the Boleyns.
They has been some discussion that George Boleyn, dean of Lichfield may have been the illegitimate son of George Boleyn, viscount Rochford, but as far as I'm aware the only 'evidence' for this is that they share a name, there is nothing else to suggest they were more than distant cousins. See Julia Fox's Jane Boleyn or George Boleyn, dean of Lichfield's Wikipedia article (which I think is vaguely accurate)
Wasn't Margaret (Meg) Shelton thought to have had an affair with Henry VII, or have I been reading too much fiction?
Mary or Margaret Shelton (sometimes written as Marg or Madge) was Henry VIII's mistress in 1534/1535. You can read more on the relationship in her Wikipedia article, 'The Mistresses of Henry VIII' or 'The Other Tudors'.
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