I feel like we're all forgetting one very important thing. Henry isn't likely going to be the one arranging Elizabeth's marriage. Mary's, yes, but Elizabeth is only thirteen if Henry dies as OTL, which means she probably won't be married yet. And I don't see the Lord Protector Somerset entertaining a Catholic marriage for the King's bastard sister. Edward, he might have to swallow the horror for, for the sake of a foreign match, but not Elizabeth. Which means Denmark or Sweden, or if they won't take a bastard, an English//Scottish noble. The Earl of Arran, perhaps?