Who was Henry VIII married to when Princess Caroline was born?

No one. Princess Caroline never existed. He had 6 children to Katherine of Aragon - 3 boys and 3 girls. Only one survived to adulthood Mary I. The other girls were either stillborn OR not named Caroline, Henry then divorced Katherine. Anne Boleyn had Elizabeth I and then gave birth to a stillborn son and then got her head chopped off. Jane Seymour gave birth to Edward VI and then died in childbirth. Henry had no child to his next 6 wives - Anne Of Cleves, Katharine Howard and Katherine Parr.

That ghost video on YouTube, if it is true, is of some other random child. Not some mythical secret Princess of Henry's. The fact that Caroline was not an English Princess name during Henry's reign should be a give away that this video shuld be viewed with some level of scepticism.