Re: Cat is scared of kitten?!
Welcome to Cat Forum. I think Jura smells/hears the kitten, but all she knows is it is something *strange* in *her* home, and it is new, different and frightening her. The best thing for you to do is to shower Jura with love and affection; reassuring her that you love her and she is safe. Take the kitten/cat intro slowly and watch Jura to be sure she doesn't get over-stressed. Kittens tend to think everyone loves them and may rush up to any/all pets, and with a pet who is uncertain or unsettled, this could cause them to react negatively. Try your best to wait until Jura shows some interest in What Is Behind Door #1 and maybe let them sniff each other through the door-gaps before you allow them to nose-nose sniff or play footsie through a door-crack.
Slow and steady. Reassure Jura and try to get her interested in the new kitty. Maybe, as she gets more comfortable, play or treats near the kitten's door so she associates the new kitten with Good Things.
Best of luck!