Ha, ha! I never heard of a nursing necklace before, but I accidentally created one.
I was going to put an elastic headband on (they make ones that are about 1/4 inch thick--just to pull the stray hairs out of your face), and I don't know, got distracted & had to pick up the baby or something, and it stayed on around my neck, like a necklace. I soon discovered that (1) it actually looks pretty good--I have different colors to match my shirts and it's a sporty/classy look and (2) DS likes to grab it instead of grabbing the skin around my neck I've got him tossed up on my shoulder. And of course, unlike my gold chain, (3) it's not gonna break.
At some point I'll have to find some pendant to add to it--something that doesn't scratch me.
--Denisemarried since 2000, mom since 2007