Don't understand my female friend?

[anonymous]

She keeps mirroring my body language, fixing her hair when she talks with me. She finds excuses to touch me, like my hands or my back and before Christmas she messaged me out of the blue. Whenever she is talking to me and her friend is there she keeps giving her peculiar faces. However, she hasn't initiated a Facebook conversation since and whenever I have recently she'll respond with only a few words and the conversations don't last. She is quite shy generally.
I don't understand, she continues with all of this flirty behaviour yet is the complete opposite when I try to text her?
Also, I'd always talk about girls I liked with her and another female friend. She'd always stay quiet when I talked about girls but recently, she tried talking about guys she thought were 'hot' when we were at the pub so I don't know if she's trying to make me jealous or something. I don't know if she has a crush on anyone or anything though.