Things were different, back then. Arranged marriages of children were done, knowing there would be no consummation (sex) until the proper age. Also, regents were appointed to make sure things went as planned.
Also, Catherine of Aragon thought God wanted her to stay in England and marry Lil’ ‘Enry.
So much history would have changed if everyone involved had followed church law from the beginning in this case and not been such a bunch of grasping power hungry old sinners.