Technically speaking, as wife of HRH The Prince of Wales, Camilla is correspondingly entitled to be called The Princess of Wales. However, we all know the reasons why she chose, on marriage to Prince Charles, to be called The Duchess of Cornwall. That is not in dispute. The anomaly will come when her husband becomes King. Obviously, we hope that HM The Queen will be long to reign over us, as we sing in the National Anthem. But, at the time of their marriage, again thinking more of the sensibilities over Diana's tragic death, it was announced that Camilla would not become Queen but would be known by the made-up title of HRH The Princess Consort.
Fine, as far as it goes, but as the children of TRH The Earl and Countess of Wessex are legally Prince and Princess and it is just the wish of their parents and by agreement with Her Majesty that they be known by titles corresponding to a non-royal earl, Camilla will be legally entitled to be called queen. As the wife of a king that will be her rank as she will presumably "rank" alongside her husband. Her rank has nothing to do with her title or "what she is called". Heraldry reflects a person's rank, not their title.
HRH Princess Patricia of Connaught was supported by HM King George V in being known simply as Lady Patricia Ramsey after her marriage, denying her own royal heritage so that she wouldn't seem to outrank her husband. However, she attended two Coronations afterwards (those of HM King George VI and the present Queen) in full royal regalia including a coronet of her rank. Again, this reflected the fact that she was a grandchild of a monarch rather than her title. In fact, Patricia was ironically assigned her Coat of Arms, with Label and Coronet, upon her marriage and the exact time she ceased being called a princess...
That instance was relatively simple. Camilla's case is a bit more complicated as she will rank as a queen but won't be known as queen. Traditionally a married king in this country is crowned alongside his wife and she is "lifted" onto a throne at his side. Will Camilla be crowned alongside Charles? If she becomes HRH The Princess Consort what will her Coat of Arms become...?
Currently, her Arms are ensigned by a coronet with one arch, just the same as her husband who is Heir to the Throne of the United Kingdom. But, as Princess Consort, will she rise in rank alongside her husband, but drop in rank heraldically and adopt a coronet with no arch? What a conundrum!
Basically, watch this space...