[![enter image description here](https://i.stack.imgur.com/EPOwE.png)](https://i.stack.imgur.com/EPOwE.png)

Consider we have a rotating disc (rotating, with a constant angular velocity w, relative to an inertial observer A). The disc has its edge charged uniformly with a total charge Q.
No doubt that A can detect loops of a magnetic field, by his pocket compass, due to the constant electric current loop generated by the rotating disc charged edge.
A is observing a current = Q/T = Q w/ 2 Pi

My question is about the observer B, in the same disc plane, which is rotating around the disc axis with the same angular velocity w, relative to A.

Would B able to detect a magnetic field by her pocket compass?

If we look to the problem from Special Relativity point of view, the charged disc edge is moving relative to B (same omega, but different distance from the disc axis, so relative speed), so her compass may detect a magnetic field.

But what if B considered herself, according to GR, constant relative to all disc points, including disc edge, considering that she would expect centrifugal and Coriolis fields? She should think that her compass is not moving relative to the disc edge, so the compass shouldn't detect a magnetic field!

Is she correct or wrong?