Don't offer her any of your feelings if you call her. Just be neutral until you know what her deal REALLY is. If the relationship was always volitile then don't even bother calling her at all because after only 15 weeks, I doubt much has changed in the way the two of you got along.
P.S. If you DO contact her, don't do it via text. Actually call her so you can gauge her voice reflections, hesitations, bullshit.
“The willingness to accept responsibility for one’s own life is the source from which self-respect springs.” ~Joan Didion