Ex sends mixed signals?

My ex girlfriend broke up with me about 8 months ago. It was a friendly breakup and mutual. Then we finally started talking to each other again about a couple months ago, she being the one initiating contact 80% of the time. We met for lunch and things went great, we rekindled the spark and talked the whole time. It's been about a month since lunch and we text occasionally, very friendly. However, usually when I see her on campus she glances at me and sometimes she even tries to bring guys into the picture when she's near me(maybe to make me jealous?) I have no idea whether she wants to get back together or remain friends, or neither. Any ideas? Also, how should I communicate with her from here on? Thanks for the help!