My cat is exactly the same, and it took a long time for her to settle down when I brought her home. I don't know what had happened to her in her first 8 weeks of life. Maybe she just wasn't socialized properly. She is scared of a lot of things, but eventually she did relax. Coaxing it with treats is good, and I'd suggest that when she comes up to you, don't immediately go to grab her. You could try stroking her slowly and gently, and she may want to sniff your hand first before she lets you do that. When she is in a room, don't pay loads of attention to her. Cats don't like being stared at, and if you just leave her to it she will eventually come to you. When she does come to you, give her a light stroke and speak to her in a 'motherese' type of voice. You know the one that mothers use with their babies. She will then associate you with comfort.
You have to keep your movements slow and controlled at first. Sudden movements in a strange environment will make her jump.
My cat is still pretty skittish. She doesn't sit on my knee, and she doesn't like to be held, but she is always next to me and follows me everywhere. Some cats just don't like being overly affectionate. My cat also runs away when someone walks towards her, but I've found that there is a way to do this without her running. You could try it with your cat. When you walk towards her or near her, simply don't look at her, and try to step around her a little.
Basically it takes a lot of patience to deal with a shy cat. You can try these little things but mainly you have to let her get used to you and your surroundings on her own terms. You can help speed this by not hassling her or forcing her, and you have to understand that she may never be a lap cat. But if you provide a source of comfort and affection then she will certainly love you, and you may find that she is fearful of others but comes to you all the time. My cat is exactly like this. In a way it's a good thing, because it makes me feel special.
maybe she had a bad expercience in her last home maybe shes a little scared from humans u will just have to be patient try some toys and catnip to help form and bond with u
dont not force her to sit on ur knee she will do this when she feels comfortable and relaxed with u
rubbing againist ur leg usually means she hunrgy so make sure u feed her enough
get her a bed or box with pet cover and add one of ur old item of clothes in there so she gets used to ur scent and it also gives her somewhere to feel safe
she may take a while to trust u and open up but it will be worth it in the
trying buying some catnip biscuits these help all cats relax and u will be able to clap her more when she eats this