*sigh* It gets so hard to do family trees in this format...
Henry Grey, Marquess of Dorset and future Duke of Suffolk through his wife, Frances Brandon, was the grandson of Thomas Grey, the YOUNGER son of Elizabeth Woodville's first marriage. Frances was the daughter of Charles Brandon, Henry VIII's best friend, and Mary Rose Tudor, Henry's sister.
Eleanor Brandon (1519-1549) - married Henry Clifford, Earl of Cumberland, had three children. Henry Clifford's mother was a Percy, and his grandfather was Sir John Clifford, known as 'The Butcher', responsible for the murder of Edmund of York, brother of Edward IV and Richard III. Eleanor's daughter, Margaret, did in fact marry Henry Stanley, 4th Earl of Derby. Henry Stanley was the great-great-grandson of Lord Thomas Stanley, Margaret Beaufort's husband (technically her fourth, but her first marriage was annulled by the time she was nine).
Katherine Grey (1540-1567) - married 1st Henry Herbert, Earl of Pembroke (married at the same time her sister Jane married Guildford Dudley and Katherine Dudley married Henry Hastings, Earl of Huntingdon), marriage annulled and probably not consummated; married 2nd Edward Seymour, Earl of Hertford (son of the Lord Protector, nephew of Thomas Seymour and Queen Jane Seymour), had two sons, Edward and Thomas. The records I found said that Elizabeth had the marriage annuled because it had been without her consent, but I wonder. I know Katherine died of a mixture of illness and heartbreak when separated from her husband, and it took something like thirty years for her husband to re-marry. It seems to have been a real love match.
Mary Grey (1545-1578) - married Thomas Keyes, a groom and/or porter to the queen, issue unknown.
Enjoy!
Regards,
Arianwen