No good will come from you getting stressed too (although it is hard not to!), and no harm is going to come from slowing it all down.
She's panicking, so all you can do is help her regulate her panic so eventually some coherent thoughts can form. I'd tell her things like 'this is normal, I am here, you are ok, the answer will come in its own time'.
Can you break it down for her - Tuesday you look together at the LJMU clearing page. That's it. Then go for a walk. Tell her before you start looking you are not going to ask her questions, you're going to help her look at what is there.
Wednesday look at the Liverpool clearing page. Then go for a walk. Again no questions.
Thursday read the UCAS clearing process page. Then go for a walk. Again no questions.
Friday, Saturday, Sunday - just go for a walk. No questions. How will she react if you say supportive things - you worked out your GCSEs, your A-levels, you're already a success, it's going to be ok - does that calm her down?