I guess I would say this: human beings do all kinds of things without even thinking about them. That means that logic doesn't play a role. But when we try to interpret the unconscious or not-thought-through actions of others logically, as though there were a reason for them...we end up making too much out of what is often (not always, but often) nothing.

Now if she did the same thing with her necklace 3-4 times in a row, I'd think that was a pattern, and that might be worth asking about.