Years ago I dropped a toothbrush in the toilet. The toilet worked fine for a couple of weeks and then one day it wouldn't flush properly. Hubby unhooked it from the floor and took it outside and use the garden hose on full blast to flush it out. Out came the toothbrush! My guess is that in your case the ring got hooked on the tweezer and they were both wedged in there. Apparently there are some skinny places inside a toilet.

Long story short - what a great ending!! I think if it hadn't been for the tweezers it would have long ago been in your sewer system! Congratulations to your mom!