I commend you for taking in the stray kitten and trying to work with her and not giving up. I volunteer for a local cat adoption agency. I highly recommend you try Feliway Comfort Zone plug in and probably the spray also. You plug the diffuser into the wall in an outlet and it has this calming therapy for cats. Sometimes it takes longer for some cats to get adjusted to their new environment than others...especially if there is already another cat there. Here is more information on the product:
It can be purchased at places like Petsmart, but they are certainly not the cheapest. I actually purchased some on Ebay as I found that to be the lowest price.
I tried some "calming" drops and they didn't work - they were expensive, too, so it was a major disappointment. She's definitely comfortable in the environment, and she doesn't run away from me as quickly or if I even enter a room, but she's still untouchable. The woman that fostered her before me said she had a ton of cats and Ed would be scared, but the woman would coax her out and she would lay in her lap and purr. I've tried holding her and she purrs, but when she thinks I've let my guard down, she bolts. This is when I first got her - I've tried everything. I tried leaving the TV on in my room for her to get used to human voices, I kept her in my room away from my animals so she wouldn't be dependent on my other cat, I tried holding her for five minutes per day, I talked to her, I got on the ground and tried to be soothing and slowly reach out to her.
I hope she gets better. She's such a nuisance, not at all malicious (except one time). I don't think I've heard her hiss or growl, but I know that before she would purr because she was half scared/half relaxed. Her claws are starting to get stuck in the carpet and there is no way I can cut them, but there is also difficulty getting her into a carrier.
Would you describe what you've done to earn her trust? (play, give her treats, hand feed her) That kind of stuff. Patience is key. She'll come around. She just needs time. You can help the situation by playing with her. Do you do that?
I've tried playing with her, but she's too scared to get too close to me. I have a laser pointer and she seems to enjoy that a bit. She's not very playful ... she watches it but doesn't chase it. She instigates my other cat and they "play fight". She is extremely curious but also very persistent and mischievous. When she thinks I'm asleep, she has crawled onto my legs or sniff me. But she is bad. She steals things from me and chews up my broom and just in general wreak havoc.
As far as food goes, I've tried giving her treats but she won't take them. I don't think she likes them. She LOVES turkey and I've tried hand feeding it to her, but the closest she's come to me is snatching it out of my hand and running away. I have tried making trails of turkey that lead to my hand and I'll lay on the floor with my arm stretched out so I am not so intimidating, but she's still very jittery.