The monarch doesn't vote. She is above and outside of the political process, and by long established tradition doesn't take sides.
Her thoughts are her own, however, if you feel competent as a mind reader.
But she never expresses an opinion.
I believe I am right in saying that those in line for the succession don't vote either.
So whoever they might favour in their thoughts, they have no influence on events, and get this straight in that ball of wool between your ears. They DO NOT cost the country a fortune, in fact the reverse.
The financial facts are a matter of public record, and indisputable.