Jw t-rex details

So that confirms they're at least breeding more Rex. Wonder if Rexy is the only adult they have.

^Most likely. The website says that the Tyrannosaurus Rex Kingdom has one Rex. However, many zoos keep multiple specimens of a species in employees-only areas. Maybe they were keeping one to replace Rexy.

Appears as though Rexy is the only Rex in the T-Rex Kingdom. They most likely have more Tyrannosaurs ready to replace Rexy though. Either an employees only section of Isla Nublar, or the island of Isla Sorna.