Now whats the reason for this mood swing in her?

10 mnths back we went on date twice and we used to meet each other alternate days as she used to invite me at her place. Then after 2mnths when I askd out she made reasons and didnt came to meet me. Since then I have asked her 4 times even recently once and she refuses every time by some reason.Now I dnt approach her , but last 20 times whenevr we both wer online on facbk she started the chat every time. On many occasions I left offline widout even sayin byee but still the next time she starts chattin to me. And always keeps frwdin msgs on my cell...so wassup wid dis gal? how do I react shud I ask her out or wat do I ask her or keep myself away?