Hi P.W. welcome, and let me say first that you are a very good friend to have found this forum and posted regarding what your friend is going through!
I would think that she would be glad to just have a person to listen to her and sympathize. You really can't fix it for her, so just being there, and letting her know that she can always talk to you will really be helpful.
Also, suggesting simple things that the two of you can do together could help her to get her mind off of her troubles for a while. Something simple like hanging out and watching movies, or baking some great treats to share would be relaxing and fun.
I hope that she feels better soon, I'm sure that with friends like you she will:)
Scaredy Cat
P.S. If you feel like your friend needs more resources for her recovery from panic attacks, you could always direct her here to H.W. We are not medical professionals, but could help her to take a step in the right direction to get the help she may need.