I for one LOVE the idea of Queen Mary I in 1547! First, this is before Edward VI's religious reforms, so it's practically guaranteed that England would return to the Catholic fold. Second, Elizabeth is only thirteen and likely to be re-educated as a Catholic. Whether that's effective or not is up for debate but there will be attempts to bring her back into the fold, so to speak. Third, Mary is only 31 and much more likely to bare children, (would the dynasty be Tudor or Tudor-hyphen depending on who she marries? I can see Mary and Elizabeth trying to keep the Tudor name going) especially sense she's avoided all the stress she had in Edward's reign.
Now on the topic of the rough wooing and Scotland I have to completely disagree with the other posters. Scotland didn't turn to France until September 1547, after the catastrophic defeat in the battle of Pinkie Cleugh. With Edward's death in 1546 this battle isn't going to happen. The purpose of the war, uniting England and Scotland under Edward, Prince of Wales and Mary Queen of Scots, is gone. Peace negotiations are likely to start after Mary's accession in January, if nor earlier. She has little reason to continue the war and every reason to disengage from a conflict that will bring her no advantage. So with the Rough Wooing over the Scottish Regents have no reason to offer their Queen to the French Dauphin. A French candidate would still be the preference to be sure (maybe Louis de Valois survives infancy?) but there's no reason to force a union or send little Marry to the French Court.
For Mary I's marriage, a Habsburg match is the most likely choice but I'm a little unsure who would be the primary Habsburg candidate would be. It would likely come down between Infante Felipe, Principe de Asturias, Archduke Ferdinand (Emperor Ferdinand I's second son, who OTL married morganaticaly married Philippine Wesler) and the Portuguese Infante Luis, Duque de Beja (who was proposed as Mary's husband by Emperor Charles multiple times OTL). All I can say is there's no chance in hell of a French marriage. Ignoring the lack of ranking candidates the French had been pro Anne Boleyn and are the hereditary enemies of Mary's closest supporter, the Emperor Charles. Marrying a Frenchmen would be a betrayal of the man who, in her eyes, stood by her during her darkest days. As for an English candidate, maybe Edward Courtenay, Earl of Devon? The reasons that made him attractive OTL would still exist TTL, but the match would bring England little advantage and be fairly low-ranking.
Will probably add more to this later.
