Shared dreams

When I was between 9-11 I stayed the night with a cousin, I had a dream that I was driving a car with my Grandma in the passenger seat. Suddenly cats began to crawl all over the car, we were forced to the side of the road. Inside the car we were frantic, my grandmother instructing me to keep them out. The cats were meowing loudly, sort of in a sinister way that I can not adequately express in words. They began to unlock the doors, I moved from rear to upper seats locking the doors while watching another began to pop up. Somehow a large black cat gets inside, he is sitting profile facing me, looking at me. I am terrified. He raises his paw and there is a singular claw, gleaming and sharp in the light of the moon. He brings it down toward my face and I throw up my arms....I wake up at that moment, and there is a bleeding scratch on my arm. I didnt tell anyone about this dream for a long time. It sort of freaked me out and I felt sure Id sound crazy or be told I was making it up maybe. The dream bothered me for years. Later as I became an adult, I assumed id likely scratched myself flailing about in my sleep. Chalked it up to a kid's imagination. Tonight my sister, who is seven years younger than me, told me about a dream she has had a few times. She is in a car, or sometimes a rest stop off a highway. With her is our grandma, myself, and our aunt. They are surrounded by cats who she says were hissing, much like in my dream they try to keep them out but the cats make it inside. A large black cat with a white mark on its head attacks my sister, as it does she wakes up and finds scratches on her arms, face etc... My sister says she thinks she was about the same age as I was when she had the dream. There are no traumas involving our grandmother. Our grandmother never had house cats as pets. Due to our age differences at the time of the dream, it's something we just never discussed with one another, each of us admitting tonight we still don't like to tell people about it. It's just weird. I am not a religious person, I do not believe in God. I am a very fact-based and evidence proven kinda girl. It is hard for me to imagine that this dream has some value-but it is very odd that both my sister and I had some version of the same nightmare Googling has done no good, I got an education into the spiritual meanings of cats and a few articles on people having shared dreams at the same time, yet ours were years apart. It's nearing 4 am and I am still awake pondering this and I am just exhausted, confused, and a little anxious I suppose. Any ideas?