Need some help!

I adopted a 5 yr old spayed DLH. The rescue I got her from said she was a little shy, but should come around in a couple of weeks. Well, I've had her for almost 2 months and she is still pretty shy/timid. She stays upstairs in a bedroom with the door always open. Her cat box is in the hallway. We have gotten to the point where she will come to me and allow me to pet her head/neck/chin only. Gives me love bites (?) if I venture to her sides. She plays like crazy and is very food motivated. If I'm on the bed playing with her and I get up she jumps off and heads under the bed most times. This morning she was laying next to me - yes, this has happened over the past week she will actually lay next to me only at night! She was laying next to me and I lightly scooped her up to give her a kiss on the head - she was not happy! I'm wondering how I can try and acclimate her into letting me try and pick her up/hold her. She comes up to me mostly in the middle of the night. She plays alot at that time also. Can I just periodically try and pick her up/hold her? I'm trying to figure this out because she needs to be brushed and nails trimmed. I also have Feliway Optimums upstairs and down in the living room. She will sometimes come down to the first level after we're all in bed. I would like to eventually move her food down to the kitchen also. Thanks for any recommendations. The cats I've had in the past I got as kittens, so this is new to me.