hen pecking at egg

I have a hen that just hatched one chick; she's been sitting on about 10. She was off the nest getting a drink and when she came back she pecked an egg that was starting to hatch; and pecked hard. I was afraid she's kill it and not knowing why she was pecking it, I pulled it, helped it out and stuck it under her (it is now fine). I've never seen a hen try to "help" a chick hatch so don't know if she was being good or evil . Any thoughts??? Thanks!

I would guess she heard it peeping in there. I vote for "good."