This is a very sad situation. The grandmother is at fault for not being responsible watching her granddaughter or her own dogs.
I was a Special Ed teacher for 15 years and have seen all sorts of children.
Not knowing this particular child, I can't judge her actions as vindictive or immature. That the mother is treating this as no big deal concerns me, accident or not. I feel that this family has no business having pets.
I just felt sick after reading this earlier, some children have no remorse, time will tell. My girlfriend who is still a teacher says their school is having a no pets policy in the classrooms now because of the death of classroom pets caused by students