Female Dating Advice Please: Calling a girl?

I went out with a girl a couple of times last summer but because of some missed communication we stopped seeing each other. I then saw her over Christmas randomly and called her a few days later to ask her out but she was seeing someone. I would like to see if she is still seeing someone. Would it be reasonable to call, text, facebook her, or is it a bad idea altogether. I kinda feel as though she would have called me if she had become single or was at all interested, but you never know. Part of my concern as well is that the last time I called her she was seeing someone, so I dont want it to seem as if I dont respect that, but there is no other way of finding out if she is seeing someone. What should I do? Serious Advice only please.Female Dating Advice Please: Calling a girl?
Send her a message on facebook...kind of a ';long time no see, just checkin in with you to see how you're doing'; type of message. If she responds, then she at least still wants to be friends. Then you can go from there. If she doesn't, leave it alone.