I been in that situation. I think you said ask her directly, if anything is wrong? or if she upset with you?<br />
Hopefully she'll explain the situation, and if they was a mistake from your part, you can apology and all should be forgiven. If she decides not to tell you, best to let her deal with her own issues, and probably taking her frustration out on you, and nothing personal.
Leave her alone.
Sometimes just sitting and NOT expecting her toshare or discuss anything is what will help
At least she gave a reason. That is something. *grimaces* You are a kind man. Give her words, kind friend. Tell her how you feel. PM on facebook then. She won't skype about this. Just try.
Leave her alone till she's ready