My old cat hates my new cat!?

I have a spayed feral female cat that me and my family hand raised to just love us. We have had her about a year now and we recently got a male domesticated kitten that is about three months old. We introduced them together but my resident cat hisses, growls, and swats at my new kitten. She tries to show her dominance but he doesn't respond and just stares at her, we think he is not responding because he wants to be dominant but she will not let him be. She is not hissing as much but we need better ways to get them used to each other. Please help!