After being apart for a year, how would my cat interact with her siblings and mother?

I would say most likely, the cat will not "recognize" the other cats from her family.

I will tell you why I say this. *I* am not a behavioral scientist, but we had to see one when our cats were fighting years ago. They were great friends before a stray in the neighborhood that was spraying and walking around the ground-level windows caused the aggression.

When we went to see this professor at the university the first thing she had us do was to separate the cats for a month so we could "re-introduce" them. She said that after that long, the cats would not remember each other as friends of enemies (which was great for us, as we were then able to get them back together). It was a long haul for us and this professor gave me a ton of tips as well as many little "nuggets" of insight into cat behavior.

I think that even if your cat "remembered" the smell, it will still react to the others for what they are - other adult cats.

I would not recommend the reunion of cats - but since you are friends with the Mom's owner, maybe you can have a people-friends reunion. :)

4 years

Cats do not have the same sense of "family" as we humans do. The fact that this is her mom and sibling will make no difference to her. Cats either like another cat, or do not - the fact that it's a relative doesn't matter. Your cat won't like them, especially if you just dump all of them together in a room. Cats need to be introduced gradually if you want them to eventually tolerate each other or become friends.

Not such a good idea - the end result is only going to be hissing, growling, and other signs of displeasure.

I'm guessing that maybe after a year your cat wouldn't remember its mother and its siblings at first, and maybe it will never remember them. After a little while though, it might realize it likes the cats even though you said it doesn't like other cats, but it might feel a connection with them that it can't quite identify and might keep your cat from fighting. Either way though, I would keep a close eye on them the whole time until they feel comfortable with each other in case they start fighting. Hope this helps, an good luck!

Oh no, it would NOT go well. Several years ago, my mom adopted a boy and I adopted a girl from the same litter. While my mom was on vacation a year later, I babysat her boy at my house. My girl was furious - she is not fond of other cats either and she did not recognize him as family. She viewed him as an interloper.

Cats aren't anything like people in that department. Though cats are great moms while their babies need them, once they're out on their own, that's it. Cats never move back in with their parents!!

Sometimes, but it is rare. As a kitten, the mother licks the kitten, putting her scent on him or her. A grown cat won't have the mother's smell. And, once they reach adulthood, they view each others as rivals for territory and intruders.

Its a really sweet idea, but I think putting all the adults together like that will only cause trauma.

Cats memory is constant if its environment is constant.. like you... he knows you... if mom and bros and sis were taken away... memory fades in hours... so, your answer is no... mom bro sis are just other cats to him now... possible insest and occur if not spayed/neuter... fights, or just sniff my butt and i'll sniff yours and bye

Highly unlikely after one year.

it would have remembered if it had been older, and had lived a while with them, especially the mother