I'm still waiting for Paizly to accept Jax. Jax has been here almost two years and Paizly still hisses, growls, spits and screams at him. Of course Jax is a little brat and instigates it. But usually he just wants to play and Paizly will have none of that.
However, the hissing at you....that will eventually fade. Raven is completely frazzled right now. Just make sure she gets one-on-one attention, as others said, and she should calm down.
I know its super frustrating right now. I went through the second guessing bringing Jax home. I've ruined Paizly's life. I actually sat and cried sometimes. Now I catch Paizly sort of attempting to play with Jax. But when he fully engages with her she flips out and hisses, screams, growls. Sometimes it sounds like a full blown cat fight and it's only Paizly yelling. That's the only time I step in and remove Jax. Otherwise I let them be.
This morning Jax was in a super playful mood. He was running all over the house. He chased Paizly and she flipped out on him. I tell Paizly "he's only trying to play with you". She was perched up on the table next to the bed and every time Jax ran near her she leaned down and extended a paw. She didn't hiss or growl. It was like she wanted to play but just couldn't bring herself to do it. She's such a snob!
Oh btw.............Prudence is flippin ADORABLE!!! :D :D I can't wait to watch her grow up. And I bet within a few months you'll be posting pictures of her and Raven all cuddled together. And I'll be super jealous. :p