Wow! This story packs so much for being such a short story! I love it. I took this as a story about the cyclical nature of violence. The wolf boy's relationship with his hen mother was created through an act of violence, which he then repeated with the bunny girl. We never see Hen Mother hurt Wolf Boy and he doesn't remember the death of his parents until he has a fit of violence himself. Therefore we can assume they had a loving relationship, yet she still traumatized Wolf Boy even if that wasn't her intention.
You have to wonder if Hen Mother herself was also a victim of the same trauma and that's what caused her to kill Wolf Boy's parents. I also want to point out that Wolf Boy didn't remember the violence and didn't seem inclined to it at first. It's not until his former "friends" pushed him too far. So the entire blame is not on Hen Mother. Wolf Boy's act of violence was also a product of the society that would not accept him. I think the story sadly hints that this is something that will continue too.
I hope we get more stories by this author.