Hello all. We were cat owners for over 16 years but sadly our two girls both passed in the last year. After a few month my wife and son convinced me it was time to extend the family. We found three kittens from a rescue (foster) and decide to adopt all three. 2 girls and 1 boy all were about 3 months old. We have had the kittens for about two weeks now and they are or were super lovable and snuggly. The strangest thing the other day the one girl was fine and then about an hour later she started hissing at us and growling. In fact she is hissing at everything. She has continued to do this but other times I see her playing and running around like nothing is wrong. Concerned she may be in pain or eaten something we took her to the vet to be checked. He said he didn’t find anything physically wrong with her. I am not convinced he did a good enough check. He said it may be here personality coming out and since she was a stray that was rescued it could be something else. He basically said some cats are crazy. I am concerned as we have the two other cats and a child. It is just weird she flipped so quick. Any advise?