Yep all you can really do is give her time and offer your support. She doesn't seem to be ready to talk to you about this yet so don't keep asking her to tell you - she might in her own time, if not she'll move on and things will hopefully get back to normal between you. Make sure she knows you're there to look after her if she needs you, but don't act too keen to find out. Your intentions are good, all you want to do is help, but she may see it as interfering. You sound like really good friends, it's just a small disagreement and hopefully everything will work itself out in the end.
Good luck and don't worry! Bottekrank x