Hi Balletmum1972,
Here are a few tips which might help.
Have you asked her teacher if she can also do the class a grade above her own one 'just for fun'? It really helped my daughter, as she had more time to learn the syllabus and was able to progress up the grades more quickly. It also meant that she already knew steps that she was asked to perform in auditions. And does the school have non-syllabus / free work classes?
The English Youth Ballet auditions are really good, as parents get to watch, and you can then see the other children of a similar age, and see what the standard is like.
Also ENB, Central and the RAD do workshops and dance days which are good fun and will help your dd with her confidence when dancing in a different studio - this really helps when auditioning.
At Tring, check out their Reach4Dance dance days and residential Christmas and Easter courses - your dd might also like to audition for the Tring Park Associates, which are syllabus classes to be taken alongside the ones at your usual school.
Finally, the National Youth Ballet takes over Tring for a couple of weeks in the summer to rehearse for their performances, and they run a one-week non residential outreach course alongside (there is no audition) which my dd has done for the last two years and had a fabulous time.