I just lost my kitty and her sister keeps hissing and growling at us

I had two cats, both girls and sisters. Today i found one of them deceased on my apartment balcony and it was horrible, i panicked and started sobbing and my husband picked her up in a rush so we could take her to the vet and her sister went crazy and attacked him. She keeps hissing and growling at both of us now, it feels like she thinks we did it :( She was just 3 years old and was completely fine at 5 am when she wakes us up for food every day, i found her at 7:30... Can someone help me cope? I don't know what happened :(((

There was scorpio sightings a few days ago at my complex, but i have never seen one here in 7 years and already searched the apartment after i came back from the vet... her eyes were still open and her little tongue was hanging out please i am so confused and scared