Just an odd thought here and perhaps someone could clarify it for me what the actual rules and regulations and all are.
To me, if lets say William comes to the throne and Catherine is then only titled and styled as The Princess Consort, wouldn't that make the marriage morganatic bu having a lesser rank and style than her husband? Wouldn't it take an act of Parliament to redefine morganatic and add that as the mother of the future monarch, he/she is entitled to can can inherit the throne along with whatever else?
mor·ga·nat·ic (môrg-ntk)
adj.
Of or being a legal marriage between a person of royal or noble birth and a partner of lower rank, in which it is agreed that no titles or estates of the royal or noble partner are to be shared by the partner of inferior rank nor by any of the offspring of the marriage.
I think its best left alone and a King has his Queen but no man should outrank a Queen.