I have the same thing with DD fondling my elbow. I'm starting to feel violated by it.

I weaned DD at 23 months by saying they were sore so I couldn't feed her....it worked but that's when the elbow thing started.

I'm getting close to putting band aids on them and doing the 'they're sore' thing again and hoping it will stop her.

It's really hard because you don't want to take away that comfort from them, but the frustration of it is too overwhelming... For me anyway.

Hope you get it sorted soon