Do cats remember their siblings? I have a kitten but they got seperated at birth. We are getting one of her brothers back (owner cant take care of him anymore), will the siblings remember eachother?

Difficult to answer as animals judge by smell and the brother will smell different to her now because of being in a different enviro. I guess. My experiences with cats seem to point to the fact that they don't know even when they havent been separated. But even so that is no reason why you should not take the male on. Many cats make friends whether they are siblings or not, especially when they are both young.

I personally think it depends in the cat. Like how smart the cat is and theire memory. It's kinda like people, some are smarter than the others and the others are not. If you know your cat a lot, than this should be easier to figure out but (I will tell you that you probs. Won't know the answer when they meet again) if you don't than this should be harder. If you know your cat is smart as a fact than maybe, but you probs don't know about the other, I'm not sure if this confusing answer worked but I hope it did a little!

Its hard to tell maybe they can from sense of smell

I don,t think so cats remember their siblings.I had 1 cat.She gave birth to 4 kittens.1 of them was male and others were female.Male gone away.But after 1 year he was back and mate his sister.