How do I help my girlfriend relieve stress?

My girlfriend is currently in college (as am I) but she is really trying hard this year and working two jobs at the same time. I know that she is already going through counseling but how can I help reduce her stress level when she comes home. We have tried but its not fun because midway through she has panic attacks. Also she was abused a lot as a kid, so I'm not sure if that has something to do with the stress or not. What do I do to help her? How do you stop a panic attack?