I don't want to make the world seem less beautiful to you, and so I hesitate to respond at all, but no claims of this sort have ever held up under scrutiny.

Human perception is not perfect, we're subject to seeing things that aren't really there and experiencing sensations which we regularly mistake the source of. People like to attribute meaning and importance to meaningless things in their lives because it makes the world seem more orderly and friendly. More fair and human.

On the other hand, logic and the scientific process are very sound indeed. They stand up under repetition, across cultural boundaries, across time. We've built an insanely productive and powerful globe spanning civilization largely on the back of science. That isn't to say everything done with science is good, but that science is proven. It works.

If a necklace gave you welts, almost certainly something in the alloy caused an allergic reaction. This is in fact pretty common, a friend of mine can't wear most piercings because of several metal allergies.

Melting rings on your fingers (barring a few metals which are liquid at or close to room temperature, but therefore not used for rings) would cause irreparable and permanent damage to the tissue, rendering the fingers unusable and requiring amputation. Deforming metal is much simpler and much jewellery is made out of fairly malleable metals, this is probably the most your sister has done. That or there was something other than metal coating the ring, seems feasible.

Lastly, on the topic of energy in general. The layperson usage of the word leads to all sorts of confusion. There isn't anything mystical or magical about energy, it's just a description of the ability of a system to do work. It's pretty well understood and we can describe how the mechanics of this work for almost any process, those we can't we have a pretty good idea. It's worthwhile to try and break down psychic and other such beliefs scientifically and see how they stand up.

PS: It's 4 AM here and I'm sleepy, maybe this is too rambly. I'll reread it tomorrow and see.