struck me as unfamiliar.
Nope, it’s been quite familiar to even someone several hundred years ago.
(This is not the same as her mother being Queen Elizabeth I, which was the tudor queen from the 1500s, wife-of-king queens don't take up a number).
It's a weird bit of asymmetry to the husband-of-queen title being decided on an adhoc basis, having been a prince of denmark, prince-consort of the united kingdom and prince of the united kingdom respectively.