Try assessing her in supine or sitting so that you can reproduce the pain, yes bring it on! Then reassess neck movements, retraction etc to see if they have any effect. I would suggest supine (i.e. Cx unloaded) as a preferred first choice. See what you find and then get back to us.

Can you give a bit more insight into the actual exercise she was doing in the gym when she suffered the injury? 8o