Dwarves have a funky way of valueing things. They go berserk if a single "masterpiece" bolt (of which they made hundreds) happens to fall into the chasm with an enemy, and yet they are still "estatic" after losing 6 children.
My metalsmith arrived with a husband, and over the years they have had 9 children, and recently a fire man popped up when the metalsmith happened to be working at the magma forge and most of her children had come to visit her. 6 children died very quickly (they were all clustered around the forge with the mother, which is exactly where the fire man appeared). She is still estatic, the father is still estatic. In the thoughts it mentions losing a child recently, but still estatic. Then a bit later some ratmen attacked, and my elite crossbowman pumped them full of masterwork iron bolts. One bolt stuck to a ratman, and the force of it knocked the ratman into the chasm. The lost bolt triggered the metalsmith to become miserable, and then tantrum and destroy the forge she was working in (incidentally, killing another child who happened to be visiting and fell in the lava).
So dwarves care for a SINGLE masterwork bolt out of hundreds far more than they care for 6 out of their 9 children? Talk about bad parents. The only children of theirs left is the baby she is carrying around and the one that is in his bed recovering from a yellow head wound due to the fire man, yet the father is still estatic - the only reason the mother is angry is she lost one of her bolts.