Bowles will take the title HRH Duchess of Cornwall, changing it to the Princess Consort, when Charles becomes King.
Charles had not been born yet as of 1973.
There's no indication at all in the text when he was born, so we don't know for sure. It's difficult as the system has a lot of trouble dealing with statements about existence or lack thereof.
( z1 bear :polarity - :ARG1 ( z2 person :name ( z3 name :op "Charles" ) ) :time ( z4 yet ) :time ( z5 as-of :op ( z6 date-entity :year 1973 ) ) )