Hi guys, I (18) got really mad at my little sister (16) because when she was going out to go to school she opened the gate and our big guard dog quickly ran through the gap of the open gate and eventually our dog killed a kitten.

In my perspective, I was in my room in front of my laptop then suddenly i heard the gate open, only the two of us in the house so i figured shes out to go to school, after what i was doing on my desk i went out of my room to check on the house and i saw outside the window the gate was left open, immediately i went outside to look for our dog and to my shock there's our neighbor's orange kitten lying in the pavement dead with a bunch of saliva, and now im calling out for our dog, she didnt wanna go inside, and was running away from me, i had to carry her to our house.

after that, things were running in my mind, i think when i heard the gate sound open, our dog quickly ran through the gap as she always does, and my little sister, didnt bother chasing after and taking her back to the house maybe because it was too hot we live in a tropical country so its extremely hot outside or maybe she is running late to school so she decided not to take her back or both.

when i confronted her about what happened, she said i was crazy for even blaming her for the death of the orange kitten, since she didnt even know a kitten would be there to be killed by our dog, but i argued that, its her negligence as a dog owner that killed the kitten, and she didnt even have guilt on what happened, just shrugged it off, so i tried to tell our mother what happened and she just laughed at me like what im saying is ridiculous, that really stuck on me, because i really thought it was something to be addressed and talked about, i thought mom would go on and talk to her to prevent it on happening again, but it felt like, they dont really care.

so reddit am i the asshole for getting mad at this?