Pony club Gold level training prepares centre based riders towards their C Test, in a progressive way split to three semesters.
Pony Clubbers need their D & D+ tests before entering C test, but there is no official requirements regarding training at centres. If your daughter is a competent rider, the centre might choose to allow her to join in on gold training and take D & D+ tests & first Gold assessment at the end of the first semester (these are arranged by centre rather than external assessors).
Pony Stars is relatively new scheme by BHS, which provides BHS centres with structure to junior courses. The awards are for under 12’s, but I’m guessing her centre is allowing kids of all ages to join with training.
They might then progressively asses her in ‘Challenge awards’ which is adult version of Pony Stars.
Which one is best for you probably depends on the centre and your daughter.
The advantage of Pony Club is that it is very structures, tried & tested and overseen by national organisation. There are usually more cost commitments though & they have to be willing to learn all aspect of the syllabus.
If your daughter is planning career with horses, Pony Club is probably the better option, wallet allowing.
The assessments prepare children being watched and ‘judged’, and if she manages to reach and pass B test, this allows direct entry to BHS Stage 3 (although generally centre memberships only train up to C & C+ tests).
Also, her telling her new college mates she did Pony Club will earn more brownie points than that she did Pony Stars, not that it should matter.
In Pony Stars / Challenge Awards the instructor will usually asses the individuals in their group as they train, although centre may choose to run ‘assessment days’.
If I was teaching both Pony Stars and Pony Club, there would probably be sligh tonal difference. At Pony Stars I would treat the kids more like hobby riders (nothing wrong with that) and in Pony Club as potential future employees.
Hope this helps and good luck to your daughter!