I just thought of something. Like his friend, Henry VIII of England, Charles Brandon was a serial monogamist, so he's most likely going to remarry. But who would he marry? On one hand, he may remarry someone connected to the King of England. On the other, he's probably going to try for an heiress. Here's some ideas:
Margaret Douglas: His niece by marriage. Unmarried at the time of Mary Tudor Snr's death. Right age. Only legitimate child of the Earl of Angus, and thus his heiress in all but his title.
Mary Tudor: Eldest child of Henry VIII of England. As of 1533 considered legitimate at court, but legitimate under Catholicism.
Anne Bourchier, 7th Baroness Bourchier: English Baroness in her own right. Married unhappily to William Parr, who divorced her OTL in 1543, after she had an illegitimate child. ITL, if she goes with Charles Brandon, he could marry her after the divorce, which could work.
Frances Plantagenet: Daughter of the illegitimate son of Edward IV of England, and thus the cousin of Henry VIII of England.
For my money, Margaret Douglas or Frances Plantagenet are the most likely. If he marries Margaret Douglas, then she could still marry who she did OTL, which would work.
Margaret Douglas: His niece by marriage. Unmarried at the time of Mary Tudor Snr's death. Right age. Only legitimate child of the Earl of Angus, and thus his heiress in all but his title.
Mary Tudor: Eldest child of Henry VIII of England. As of 1533 considered legitimate at court, but legitimate under Catholicism.
Anne Bourchier, 7th Baroness Bourchier: English Baroness in her own right. Married unhappily to William Parr, who divorced her OTL in 1543, after she had an illegitimate child. ITL, if she goes with Charles Brandon, he could marry her after the divorce, which could work.
Frances Plantagenet: Daughter of the illegitimate son of Edward IV of England, and thus the cousin of Henry VIII of England.
For my money, Margaret Douglas or Frances Plantagenet are the most likely. If he marries Margaret Douglas, then she could still marry who she did OTL, which would work.