Now you have said that she is "all 11-plussed out", I suggest that you focus only on the problem question types.
Use the Learning Labs papers, mark out the types that she finds difficult and focus solely on those. Simply watch her work, question by question.
Are both hands working? Where is the pencil? Time her yourself secretly by counting the time for each question roughly in your head, rather than using an electronic timer. Watch what she is doing and give her confidence boosting tips afterwards. If she is dreadfully over the "30 seconds per question limit", deal with it, but otherwise, try to ignore a few seconds variation. These are the questions that she finds hardest, after all!
I think that would be better than more full practice papers at this stage, unless she is having timing problems.
I would also remind her how little she has left to do before it is all over, and what the treat will be after the second test!