I currently have a rescue cat, approximately 18 months old, plus 2 sisters around 11 - 12 weeks.
One of the kittens is trying to make friends with the 'big' cat but it just isn't happening. She's making all the right moves showing she is not wanting to fight but to play. She lays on her back in submissive posture while the older one spits and
swears at her. I just don't think the older one understands 'play'. She was rescued from the streets of Malaga in a sorry state, with her tail broken in 2 places and a number of teeth missing, including a canine. I assume her time was spent concentrating on survival and not on being a kitten.. How sad is that....