She has no way of knowing it but this is Fëanor. If there is anything stupid a person can do while handling metal he most certainly already had done it when he was barely a couple of hundred years old, got yelled at by a master smith and his then-future father-in-law, thus learning for the rest of his existence to never ever do it again.

There is not a single person parts of her arm will ever be safer with.

"At the risk of sounding painfully obvious, but have you tried zinc?"