>>296071585
Import the earring mesh into blender, move them into the right spot, transfer mesh data vertex groups etc. make sure source layers selection is all. (basically, brings the weight painting from the ears to the earrings) You should also join meshes as a simple optimization thing. Boom, done.
If you want to try to do it purely by unity you could try to make sure the earring object is attached the ear bone that's moving, but I doubt it'll move 100% accurate.
If the ears are moving via shapekey then you have more work to do, you'll have to edit where the earrings are in the shapekey itself in blender.
Good luck with your glow in the dark thot/wolfboy.